JPH0424285Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to oil fan heaters, and is particularly applicable to oil fan heaters that use an electromagnetic pump to supply fuel to a combustor, vaporize and burn the fuel, and perform heating. Regarding fan heaters.

[Prior Art] Recently, switching of the combustion amount has become common in vaporizing combustors such as petroleum fan heaters in which liquid fuel is vaporized in a vaporizer and burned on a burner flame hole. The switch can be switched in multiple stages, and at the same time, the range of combustion amount between strong and weak settings is large, specifically, the maximum combustion amount is 3300 kca.
The combustion amount is changed to a ratio of approximately 3:1, such as a minimum combustion amount of 1000 kca/n and a minimum combustion amount of 1000 kca/n. This switching of the combustion amount is performed by changing the pulse width of a drive pulse signal applied to a drive circuit that drives an electromagnetic pump to control the amount of fuel supplied.

Figure 6 is the background of this invention and is a schematic block diagram of the oil fan heater of this invention.
The figure is a waveform diagram showing the drive pulse signal of the electromagnetic pump.

First, the general structure and operation of a conventional oil fan heater will be described with reference to FIGS. 6 and 7. The DC voltage is made constant by the DC constant voltage circuit 1, and the constant DC voltage is supplied to the microcomputer 2 via the DC power supply line.
given to. The microcomputer 2 outputs a driving pulse signal having a pulse width A and a period B as shown in FIG.
is applied to the base of transistor 5 via.
The base of transistor 5 is grounded via resistor 8. A resistor 9 is connected between the collector of the transistor 5 and the DC power supply line, and the emitter of the transistor 5 is connected to the base of the transistor 6 and grounded via the resistor 10.
An electromagnetic coil 3 and a resistor 4 of an electromagnetic pump for fuel supply are connected in series between the collector of the transistor 6 and the DC power line, and a diode 11 is connected in parallel to the electromagnetic coil 3 and the resistor 4. .

Furthermore, a frame sensor 21 , a temperature setting section 22 , and a room temperature detection section 23 are connected to the microcomputer 2 . The flame sensor 21 detects the state of the flame, the temperature setting section 22 sets the temperature to be heated, and the room temperature detection section 2
3 detects the temperature in a heated room.

When the microcomputer 2 outputs a drive pulse signal as shown in FIG. 7a, the transistor 6 becomes conductive when the drive pulse signal is at "H" level, and as the transistor 5 becomes conductive, the transistor 6 also becomes conductive. . As a result, a pulse current determined by the electromagnetic coil 3 and the resistor 4 flows. The pulse width A and period B of the driving pulse signal are controlled by the microcomputer 2, and when set to strong, the pulse width A becomes wider and the period B becomes shorter, as shown in FIG. 7a. Conversely, when the setting is weak, the pulse width A becomes narrower and the period B becomes wider, as shown in FIG. 7b. At the time of strong setting, the pulse current flowing through the electromagnetic coil 3 was adjusted by the resistor 4 so that liquid fuel corresponding to the maximum combustion amount of 3300 kca/n, for example, was supplied.

[Problems to be solved by the invention] In the conventional oil fan heater configured as described above, even if the combustion amount can be adjusted using the resistor 4 when the setting is set to high, the amount of combustion cannot be adjusted when the setting is set to low. This had the disadvantage that the combustion amount varied widely when the setting was set to low. On the other hand, if the resistance 4 is used to adjust the combustion amount at the weak setting, the combustion amount cannot be adjusted at the strong setting, and the variation in the combustion amount at the strong setting increases.

In particular, when using an electromagnetic pump for fuel supply in a combustor, the combustible range is inevitably ±25 of the set value.
Because it was necessary to ensure normal combustion even if the combustion rate varied by a fraction of a percent, a high degree of precision was required for everything from burners, carburetors, blowers, and other sheet metal parts. Furthermore, since the electromagnetic pump can only be adjusted at the strong setting, if the weak setting value does not fall within a certain range, the pump must be discarded as a defective product, which has been an obstacle to reducing costs.
Furthermore, in recent years, stability, NOx, etc. have become extremely demanding, and as a result, there is a tendency to require the variation in combustion amount to be minimized as much as possible.

Therefore, the main purpose of this invention is to reduce the variation in the amount of combustion by the combustor, and
An object of the present invention is to provide an oil fan heater in which defective electromagnetic pumps can be easily determined in the manufacturing process.

[Means for solving the problem] This invention includes a switching function that switches the flow rate of fuel supplied to the combustor by an electromagnetic pump to switch the combustion amount between strong and weak, and the temporary air amount can be adjusted. In an oil fan heater equipped with a flame sensor that detects the state of the flame, when the combustion amount is switched to strong, the electromagnetic pump has a predetermined amount of fuel to supply the combustor with the fuel required for strong combustion. A resistor adjusted to allow current to flow is connected between the drive means and the electromagnetic pump, and is regulated at the level of the flame sensor so that when the combustion amount is switched to weak combustion, the combustion amount is weak combustion. and includes a control means for applying a drive pulse corresponding to the frame level to the drive means via a resistor, and at the time of manufacturing,
When the combustor is controlled to cause weak combustion by the control means and it is determined that there is poor combustion according to the output of the flame sensor, this is displayed.

[Function] The oil fan heater of this invention supplies the fuel required for strong combustion to the combustor by passing a predetermined current through the electromagnetic pump through a resistor during strong combustion, and uses a flame sensor to ensure weak combustion during weak combustion. A drive pulse corresponding to the flame level is given to the resistor to drive the electromagnetic pump, and when a combustion defect is determined according to the output of the flame sensor during weak combustion during manufacturing, it is displayed. This makes it possible to easily select electromagnetic pumps that are malfunctioning.

[Embodiment of the invention] Fig. 1 is a flowchart for explaining the specific operation of an embodiment of the invention, Fig. 2 is a flowchart showing the manufacturing process of an oil fan heater, and Fig. 3 is a flowchart showing the manufacturing process of an oil fan heater. 4 is a diagram showing the relationship between the combustion amount near the weak combustion amount and the flame level when the flame level, which is the output of the flame sensor during strong combustion, is held constant. FIG. It is a diagram showing the relationship between the discharge amount and the period,
FIG. 5 is a diagram showing the relationship between the amount of weak combustion and the flame level when the flame level during constant combustion is varied within an allowable range.

First, the principle of this invention will be explained with reference to FIGS. 3 to 5. As shown in Figure 3, if the temporary air amount during strong combustion is kept constant and the flame level, which is the output of the flame sensor 21, is kept constant, then during weak combustion, the flame level will be relatively proportional to the combustion amount. It can be seen that there is a change in the Furthermore, as shown in Figure 4, in order to change the combustion amount, the period of the drive pulse signal for driving the electromagnetic pump is changed, but this period and the combustion amount also tend to change relatively proportionally. strong. Furthermore, as shown in Fig. 5, it is clear from the relationship between the combustion amount of weak combustion and the flame level when the flame level during constant combustion is varied within the allowable range that the flame level during strong combustion is the upper limit. If the flame level is adjusted to , the upper limit will be reached even during weak combustion, and the flame level will be high. Conversely, when the flame level during strong combustion is adjusted to the lower limit, the lower limit, that is, the flame level during weak combustion, becomes lower.

Therefore, the reference frame resistance B shown in FIG.
The reference frame level at is set as the reference frame level during weak combustion by the microcomputer shown in FIG. to forcefully increase or decrease the amount of combustion. By doing so, as is clear from FIG. 5, the combustion amount can be kept within a certain level of variation. At this time, since the electromagnetic pump is adjusted by the adjustment resistor 4 so that it has a predetermined discharge amount during strong combustion,
The weak discharge amount can be left unadjusted. In addition, if the upper limit of the driving cycle of the electromagnetic pump (for example, 110 msec) is set by the microcomputer 2 using the reference frame resistance B, and the pump must be driven at a cycle longer than the set upper limit to reach the reference frame resistance value, It is also possible to display a message indicating that the electromagnetic pump is abnormal and that repair is required during normal use. Furthermore, by displaying electromagnetic pump abnormalities during the production process, it is also possible to discover irregularities in electromagnetic pumps and defective products.

Next, the operation of one embodiment of this invention will be explained in more detail with reference to FIGS. 1 and 2.

First, in the manufacturing process of oil fan heaters, as shown in Figure 2, there are several steps (not shown).
In step SP1 (abbreviated as SP), the electromagnetic pump is assembled, and in step SP2, the resistance value of the resistor 4 shown in FIG. 6 is adjusted to be the resistance value at a strong discharge amount. And step SP3
Assemble the other parts and proceed to step SP4.
Assemble and complete the combustor. step
In SP5, set strong combustion and perform preliminary combustion.

In step SP7, the flame level is displayed on a display (not shown), and while watching the display, in step SP6, a damper (not shown) is adjusted to adjust the temporary air amount during strong combustion. Next, in step SP8, weak combustion is set using a setting switch (not shown). The flame level in weak combustion is displayed in step SP10, and it is determined in step SP9 whether or not the flame level has been automatically adjusted to produce weak combustion. If not automatically adjusted,
In step SP11, the operation is stopped, and in step SP12, it is displayed that the electromagnetic pump is malfunctioning. If automatic adjustment of weak combustion was performed in step SP9, step SP13
The product will be shipped assuming that the adjustment has been carried out normally.

Next, the operation of the oil fan heater will be explained with reference to FIG. First, step SP21
At step SP22, plug the cord of the main unit into the power outlet and turn on the operation switch. Then, preheating is started in step SP23, and ignition operation is performed in step SP24. At step SP25, it is determined whether or not ignition has occurred based on the output of the flame sensor 21. If ignition has not occurred, the process returns to step SP23 to start preheating again, and at step SP24, an ignition operation is performed. Then, in step SP25, it is determined again whether or not ignition has occurred, and if ignition has not occurred, the operation is stopped in step SP26.

When it is determined in step SP25 that the ignition has been ignited, in step SP27,
Perform forced stable combustion for 1 or 3 minutes. Then, in step SP28, the room temperature detection section 23
The indoor temperature detected in step SP29 is compared with the set temperature set by the temperature setting section 22, and the combustion amount is determined in step SP29. That is, if the combustion amount is set to a high level by the setting switch, in step SP30, a drive pulse signal with a predetermined pulse width or a predetermined cycle is output,
Drives an electromagnetic pump. If weak combustion is set, the electromagnetic pump is driven with an initial pulse width or period in step SP31.

At step SP32, frame sensor 2
Based on the output of step 1, it is determined whether or not the frame level has reached the specified frame level, and if the frame level has reached the specified frame level, a drive pulse signal having an initial pulse width or period is output at step SP33.

If the specified frame level has not been reached, the pulse width or period is changed in step SP34. In step SP35, it is determined again whether the frame level has reached the specified frame level, and if the frame level has not reached the specified frame level, the step
The pulse width or period is changed in SP34. If the specified frame level is not reached even if the electromagnetic pump is driven by outputting a drive pulse signal with a constant pulse width or period, the step
Stop the operation at SP37 and proceed to step SP38.
indicates that the electromagnetic pump is malfunctioning. If it is determined in step SP35 that the frame level has reached the specified frame level, then in step SP36, a drive pulse signal having the pulse width or period when the frame level has been reached is output to drive the electromagnetic pump.

[Effects of the invention] As described above, according to this invention, the amount of combustion during weak combustion is specified at the level of the flame sensor, and a drive pulse signal corresponding to the flame level is output to drive the electromagnetic pump. Therefore, after adjusting the adjustment resistance connected to the coil of the electromagnetic pump during strong combustion, there is no need to make adjustments at each combustion time. Moreover, the combustion amount during weak combustion can be kept within a predetermined range, and even if there is an electromagnetic pump with an abnormal fuel discharge amount, if certain conditions are set for the drive power source,
It is also possible to sort out abnormal discharge amounts and defective products.

[Brief explanation of the drawing]

FIG. 1 is a flowchart for explaining the specific operation of an embodiment of this invention. FIG. 2 is a flow diagram showing the manufacturing process of the oil fan heater. FIG. 3 is a diagram showing the relationship between the combustion amount near the weak combustion amount and the flame level when the flame level of the strong combustion amount is kept constant. FIG. 4 is a diagram showing the relationship between the discharge amount and cycle of the electromagnetic pump near the weak combustion amount. FIG. 5 is a diagram showing the relationship between the amount of weak combustion and the flame level when the flame level during constant combustion is varied within an allowable range. 6th
The figure provides the background to this invention and is a schematic block diagram of the oil fan heater of this invention. FIG. 7 is a diagram showing the drive pulse signal of the electromagnetic pump. In the figure, 2 is a microcomputer, 3 is a coil, 4 is an adjustment resistor, and 5 and 6 are transistors.

Claims (1)

[Scope of claim for utility model registration] Includes a switching function for switching the combustion amount between strong and weak by switching the flow rate of fuel supplied to the combustor by an electromagnetic pump, and the amount of air can be adjusted temporarily,
In an oil fan heater equipped with a flame sensor that detects a flame state, when the combustion amount is switched to strong, a predetermined current flows through the electromagnetic pump in order to supply the combustor with the fuel required for strong combustion. A resistance adjusted as shown in FIG. , further comprising a control means for applying a drive pulse corresponding to the flame level to the drive means via the resistance, and when the combustor is controlled to cause weak combustion by the control means at the time of manufacture. To,
An oil fan heater, characterized in that when it is determined that there is a combustion failure in accordance with the output of the flame sensor, it is displayed.