JP3039230B2 - 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 device used for an oil fan heater or the like.

[0002]

2. Description of the Related Art Generally, this kind of liquid fuel supply apparatus is shown in 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 moves up and down a plunger 106 based on an output from a pump drive control unit 105 as shown in FIG. 5, and drives a discharge valve 107 and a suction valve 108 by the up and down movement of the plunger 106. Thus, fuel is sucked from the tank 101 and supplied to the combustion section 104.

[0004]

However, in the above-described conventional configuration, if an excessive voltage is applied to the pump drive control unit 105 due to an abnormality of the power supply voltage or a failure of a component of the main unit control unit, the plunger 106 is not operated when the plunger 106 operates normally. There has been a problem that the fuel cell moves greatly beyond the stroke range and discharges an abnormal amount of fuel (a much larger amount than the normal maximum discharge amount). When such an excessive amount of fuel is discharged, the flame in the combustion section 104 becomes abnormally large on the device side, giving a user an uneasy feeling, or causing the device body 1 shown in FIG.
There is a problem that the flame spreads all over the duct 110 of 09 and the device is thermally damaged.

[0005] Therefore, conventionally, when an abnormal voltage is applied to the pump drive control unit 105 by providing a voltage detection unit, this is detected and the power supply to the pump drive control unit 105 is stopped to stop the fuel supply. However, when an abnormal voltage is detected, the plunger 106 has already moved a large distance, so an instantaneous but excessive amount of fuel is discharged, and the flame temporarily increases on the device side,
It did not lead to a fundamental solution.

In addition, this voltage detection method has a problem that it is inconvenient to use because the fuel supply is immediately stopped even when it returns to a normal state immediately, such as an excessive voltage caused by a temporary power supply voltage fluctuation. there were.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and has as its first object to prevent an excessive flow rate from being discharged even when the power supply voltage fluctuates and the like, and without impairing usability. A second object is to improve safety.

[0008]

SUMMARY OF THE INVENTION The present invention relates to the above first and second aspects.
In order to achieve the above object, a tank holding fuel, an electromagnetic pump for supplying fuel from the tank to the combustion unit, and a pump drive control unit for controlling the drive of the electromagnetic pump are provided. Is configured to drive the plunger to supply and discharge fuel by energizing the
At the same time, a regulating part is provided at at least one of the right side of the plunger discharge path and the discharge end of the plunger to restrict excessive plunger movement and prevent an abnormal amount of fuel from being discharged. And plunger movement regulation
The safety control unit that stops the fuel supply when the
There is a configuration provided .

[0009]

According to the present invention, an excessive voltage is applied to the pump drive control unit due to an abnormality of the power supply voltage or a failure of a component of the control unit of the device, and the plunger moves beyond the upper limit of the normal stroke range. The movement of the plunger is restricted by the restricting portion, and the plunger does not move beyond the upper limit of the normal stroke range. Accordingly, excessive fuel is never discharged from the electromagnetic pump, and instantaneous generation of excessive flame can be prevented. In addition, the plunger movement regulation continues for a predetermined time.
Is configured to stop the fuel supply.
Overvoltages caused by typical power supply voltage fluctuations
If it returns to normal immediately, continue fuel supply as it is
However, when there is an abnormality such as a component failure,
Shuts off the fuel supply and is safe without compromising usability
Performance can be improved.

[0010]

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, the schematic configuration of a hot air heater incorporating the liquid fuel supply device of the present invention will be described with reference to FIG.
Reference numeral 1 denotes a main body case having a warm air outlet 1A on the front surface. 2
Is a tank for holding liquid fuel disposed on the side of the main body case 1, and a detachable cartridge tank 3 is disposed on the tank. Reference numeral 4 denotes an electromagnetic pump disposed on the upper surface of the tank 2, reference numeral 5 denotes an oil supply pipe, and reference numeral 6 denotes a combustion unit which vaporizes and burns liquid fuel supplied through the oil supply pipe 5 by the electromagnetic pump 4. A combustion cylinder 7 for guiding the combustion gas upward is provided around the periphery. Numeral 9 is a duct which mixes the above-mentioned combustion gas with the indoor air flow from the convection blower 8 which covers the above-mentioned combustion cylinder 7 and is arranged rearward to produce hot air.

Next, the configuration of the liquid fuel supply device for the above-described hot air heater will be described with reference to FIGS. First, the electromagnetic pump 4
In the following description, reference numeral 10 denotes a pipe column which forms a flow path 10A for the liquid fuel in the electromagnetic pump 4, and a discharge connection portion 11 for connecting the oil feed pipe 5 is connected to the end of the pipe column. Reference numeral 12 denotes a discharge valve seat provided in the discharge coupling portion 11 and has a discharge port 12a. A discharge valve 13 opens and closes the discharge port 12a, and is formed of a magnetic material. The discharge valve 13 is opened when the liquid fuel is discharged, and closed by a discharge spring 14 when the liquid fuel is sucked.

A plunger 15 is located below the discharge valve seat 12 and moves up and down.
6 is opened to suck liquid fuel between the discharge valve seat 12 and the suction valve 17 when the liquid fuel goes upward, the suction spring 16 closes the suction valve 16 and pushes the liquid fuel upward. , Springs 20 and 21. Reference numeral 22 denotes a solenoid disposed around the pipe post 10, and a plunger 15.
The upper magnetic path 23 for transmitting the magnetic force lines from the solenoid 22 and pulling up the plunger 15 between the tube column 10 and the lower magnetic path 24 for transmitting the magnetic force lines away from the lower part thereof. Has been established.

Reference numerals 25 and 26 denote spring seats for receiving the springs 20 and 21. At the end on the plunger 15 side, regulating portions 27 and 28 for regulating the movement of the plunger 15 are formed, respectively. The restricting portions 27 and 28 are connected to the solenoid 22
Is applied to the plunger 15 so that the plunger 15 moves greatly, the upper limit of the predetermined normal stroke range (the amount slightly larger than the predetermined amount corresponding to the maximum combustion amount of the combustion amount variable width). Fuel discharge position)
The plunger 15 is in contact with the restricting portions 27 and 28 to prevent further movement.

Reference numeral 29 denotes a suction pipe disposed at the lower end of the pipe post 10, and a mesh filter 30 is mounted at the lower end of the suction pipe so as to filter dust and the like so as not to enter.

Next, the structure of the control unit for controlling the electromagnetic pump will be described. Reference numeral 31 denotes a pump drive control unit for controlling energization to the solenoid 22, which operates upon receiving an output from a combustion control unit 32. It has become. The combustion control unit 32 operates based on an operation start command from the operation switch 33, issues a fuel supply start command to the pump drive control unit 31 according to a predetermined program, and starts combustion. I have. 34 is plunger 1
Reference numeral 5 denotes a detection unit for detecting when the control unit 27 comes into contact with the discharge-side regulating unit 27. For example, when the control unit 5 makes contact with the control unit 27, a current flows and the detection is detected. Reference numeral 35 denotes a safety control unit that operates upon receiving an output from the detection unit 34.
When the output from the detection unit 34 is detected for a predetermined time, a signal is sent to the combustion control unit 32 to stop the power supply to the pump drive control unit 31.

In the above configuration, this hot air heater is supplied with fuel from the cartridge tank 3 into the tank 2 so as to maintain a constant oil level, and from the tank 2 through the oil feed pipe 5 by the electromagnetic pump 4. And supplied to the combustion section 6. Then, the combustion exhaust 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 blown out 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 32, the pump drive control unit 31 starts ON-OFF energization to the solenoid 22, and drives the solenoid 22 to start combustion. That is, when the solenoid 22 is energized, a magnetic field is generated from the solenoid 22 via the upper magnetic path 23 to the plunger 15, the lower magnetic path 24, and the solenoid 22.
5 is raised upward. At this time, the discharge valve 13 is opened, the suction valve 16 is closed, and the liquid fuel in the space between the discharge valve seat 12 and the plunger 15 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 22 is stopped, the plunger 15 is lowered to the original position by the springs 20 and 21. At this time, the discharge valve 13 is closed, the suction valve 18 is opened, and the space between the discharge valve seat 12 and the plunger 15 is filled with the liquid fuel sucked from the lower suction pipe 29.
The liquid fuel in the tank 2 is sucked from the suction pipe 29 through the filter 30 and supplied to the combustion unit 6 through the oil supply pipe 5 by repeating ON / OFF of the energization of the solenoid 22.

As described above, the electromagnetic pump 4 sucks and discharges the fuel by the plunger 15 in accordance with the output from the pump drive control unit 31. At this time, an abnormality in the power supply voltage, a component failure of the combustion control unit, etc. When an excessive voltage is applied to the pump drive control unit 31, the plunger 15 is pulled by the attractive force of the strong magnetic field, and tends to move largely against the force of the spring 20. However, at this time, when the plunger 15 moves to the upper limit of the preset normal stroke range (the position at which the amount of fuel discharged is slightly larger than the amount corresponding to the preset maximum combustion amount of the combustion amount variable width). The further movement is prevented by abutting on the regulating portion 27 of the spring seat 25, and the spring seat 25 moves only up to the upper limit of the normal stroke range. Therefore, the plunger does not move beyond the upper limit of the normal stroke range and an excessive amount of fuel is discharged as in the related art. Therefore, the flame in the combustion section does not become larger than the size of the normal range, and it is possible to surely prevent instantaneous excessive flame from occurring.

On the other hand, when the excessive voltage is applied as described above and the plunger 15 comes into contact with the regulating portion 27, the detecting portion 34 detects this each time, and the signal is transmitted to the safety control portion 35.
Send to The safety control unit 35 monitors whether this signal continues for a predetermined time, for example, 3 seconds. If the signal does not continue for a predetermined time, the safety control unit 35 continues to monitor the presence or absence of a signal from the detection unit 34. A signal is sent to the section 32 to stop the power supply to the pump drive control section 31. Therefore, when returning to the normal state immediately, such as an excessive voltage caused by a temporary fluctuation of the power supply voltage, the fuel supply is continued as it is, but the fuel supply is stopped in the case of an abnormality such as a component failure or the like where the excessive voltage continues. Will be.

In the above embodiment, the restricting portions 27 and 28 for preventing the plunger 15 from excessively moving are provided with the spring seats 25 and 28.
Although it is provided at 26, it may be provided by providing an annular rib on the tube post 10 or the like, and may be provided in any way within the flow path 10A. The restricting portions 27 and 28 may be provided on the plunger side, and the restricting portions 27 and 28 may have any configuration as long as it restricts excessive movement of the plunger 15. Is also good. Further, the regulating portions 27 and 28 are provided on both sides of the suction and discharge of the plunger 15, but may be provided at least on the discharge side, and may be any as long as the object of the present invention is achieved. But it is good.

[0022]

As described above, the liquid fuel supply device according to the present invention restricts excessive movement of the plunger in at least one of a proper position on the discharge side circulation path of the plunger and the discharge side end of the plunger. A regulating part is provided to prevent an abnormal amount of fuel from being discharged, so an excessive voltage is applied to the pump drive control unit due to an abnormal power supply voltage or a component failure in the main unit control unit, and the plunger operates normally. Even if the plunger attempts to move beyond the upper limit of the stroke range, the movement of the plunger is restricted by the restricting portion, so that the plunger does not move beyond the upper limit of the normal stroke range. Therefore, excessive fuel is not discharged from the electromagnetic pump at all, and instantaneous excessive flame generated on the device side can be reliably prevented.

Further, the fuel supply is stopped when the movement of the plunger is continued for a predetermined period of time. Therefore , when the normal state is immediately returned, such as an excessive voltage caused by a temporary fluctuation of the power supply voltage, the fuel supply is stopped. Although the fuel supply is continued, the fuel supply is stopped at the time of an abnormality such as a component failure or the like in which an excessive voltage continues, so that safety can be improved without impairing usability.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a liquid fuel supply device according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing an electromagnetic pump of the device.

FIG. 3 is a cross-sectional view of a hot air heater using the same device.

FIG. 4 is a cross-sectional view of a hot air heater using a conventional fuel supply device.

FIG. 5 is a sectional view showing an electromagnetic pump of the apparatus.

[Explanation of symbols]

 2 Tank 4 Electromagnetic pump 6 Combustion unit 15 Plunger 22 Solenoid 27 Restriction unit 34 Detection unit 35 Safety control unit 10A Flow path

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) F04B 17/04 F23K 5/04 F04B 23/02

Claims (1)

(57) [Claims] A tank for holding fuel, an electromagnetic pump for supplying fuel from the tank to a combustion section, and a pump drive control section for controlling the drive of the electromagnetic pump, wherein the electromagnetic pump energizes a solenoid. by well as configured to suction and discharge the fuel by driving the plungers, to regulate the movement of excessive plunger in at least one of the discharge side end portion of the position and the plunger of the discharge side flow passage of the plunger A regulating part is provided to prevent the abnormal amount of fuel from being discharged , and the movement of the plunger is restricted for a predetermined time.
A liquid fuel supply device provided with a safety control unit that stops fuel supply when continued .