JPH0146764B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to oil burning appliances such as oil fan heaters.

Conventional structure and its problems In general, combustion appliances, such as oil fan heaters, are
As shown in the figure, an oil tank 3 and a burner 4 are provided inside an exterior 1 and a bottom plate 2. Combustion gas A burned in the burner 4 is blown out as warm air C from the louver 7 together with indoor air B by a fan 6 attached to a blower motor 5, and is used for indoor heating.

FIG. 2 shows the main parts of the oil tank 3 shown in FIG. Pump 11 for supplying oil
is installed.

FIG. 5 shows an example of a conventional control circuit for such a combustion appliance, in which a power switch 13 is connected to an AC power source 12, and a control circuit 15 mainly including a microcomputer (hereinafter referred to as microcomputer) 14 is connected between both ends a and b of the AC power source 12. , a series circuit of the contact 16 and the sheathed heater 17 for vaporizing kerosene in the burner 4, a series-parallel circuit of the contact 18, the blower motor 5, and the burner motor 19 for supplying combustion air in the burner 4; A series-parallel circuit of an igniter 21 for igniting vaporized kerosene in the pump 11 and burner 4 is connected to the contact point 20, respectively. Also, the control circuit 15
In addition to sensors such as a float switch 10 and a thermistor 22 for detecting room temperature, a panel 24 of light emitting diodes 23 is connected to display the operating status and operation status of the circuit.

In such a configuration, conventionally, when the operation switch 13 is closed, the control circuit 15 operates the contacts 16, 18, and 20 by the action of the microcomputer 14 to burn kerosene in the burner 4, as shown in FIG. Generate combustion gas A. In addition, in FIG. 2, while oil remains in the movable tank 9,
The oil level is maintained at the height A, but when the oil level in the tank 3 gradually decreases and the float 25 of the float switch 10 drops to the OFF point B, the signal enters the microcomputer 14. The refueling lamp 23a in the display panel 24 lights up.

After the float 25 is activated, the burner burns for a certain period of time (for example, one hour), and then automatically stops burning. That is, in FIG. 2, while there is kerosene in the movable tank 9, the oil level in the tank 3 remains at A,
The kerosene in the movable tank 9 gradually decreases until the movable tank 9 becomes empty and the level in the tank 3 reaches A.
When it descends and reaches B, the float 25 closes the contact point.
Turns off and sends a signal to the microcomputer 14. From this point on, the microcomputer 14 turns on the refueling lamp 23a to predict the need for refueling. At the same time, the microcomputer 14 starts calculating the remaining amount of fuel from this time, and automatically stops combustion after a certain period of time.

However, conventionally, the microcomputer 14 starts calculating the remaining amount of time after the contact 25a of the float 25 turns OFF, so the amount of kerosene in the tank 3 is low from the beginning.
Even if the contact 25a of the float 25 is already OFF, the operation switch 13 is closed,
When the microcomputer 14 starts operating, since the contact 25a of the float 25 has already been turned off, it automatically starts calculating the remaining amount, and does not stop combustion until after a certain period of time. For this reason, if the initial remaining amount in the tank 3 is extremely low, the oil will run out midway through, making the fuel unstable and producing significant gas and odor, which is not preferable.

Furthermore, if an oil fan heater is used without maintenance for two to three seasons, water may accumulate in the tank 3, and corrosion caused by this water may cause a hole in the tank 3, causing oil to leak. Even in such a case, the microcomputer 14 attempts to continue combustion until the remaining amount of time is calculated, causing premature kerosene exhaustion, which is undesirable.

Purpose of the Invention The present invention was made in view of the above-mentioned problems, and its object is to accurately detect the amount of kerosene remaining in an oil tank and to prevent the kerosene from running out prematurely.

Structure of the Invention In order to achieve the above object, the present invention detects oil shortage even during non-combustion, such as before the start of combustion or during combustion interruption, that is, turns off the contact 25a of the float 25.
It is configured to detect this, and when this oil shortage is detected, it is determined that there is an abnormality and combustion is stopped.

DESCRIPTION OF THE EMBODIMENTS One embodiment will be described below with reference to FIGS. 3 and 4. The same parts as in the conventional example will be given the same numbers and the explanation will be omitted, and only the different parts will be explained. The microcomputer 14a, which is the main body of
It is configured to perform the operations shown in the flowchart in the figure. In other words, in FIG. 4, 26 is contact point 1
6 is turned on to energize the sheathed heater 17. 27
is a routine to check whether the temperature has reached a sufficient temperature to vaporize the kerosene; if the temperature has not risen sufficiently, the process goes through the oil float check subroutine of 28 and returns to 26. 28 is float 2
In the subroutine to check whether contact 25a of float 25 is OFF, contact 25a of float 25 is turned off.
If 5a is OFF, the refueling lamp 23a is turned on in the routine 28a, and a reset is performed to stop the operating state in 28b. Further, at 28C, the reset lamp 23b is lit to warn that there is an abnormality. On the other hand, when it is determined that the preheating is sufficient at step 27, the contact 16 is turned off at step 29, thereby turning off the sheathed heater 17 and simultaneously turning on the contact 18.
Then, turn on the blower motor 5 and burner motor 19. This state is called prepurge and is continued for a certain period of time (for example, 10 seconds) in the determination routine 30. After pre-purge, the contact 20 is closed at 31 and the pump 11 is turned on to start combustion. 32
detects the status of the contact 25a of the float 25,
This is a judgment routine that has different branch destinations depending on whether it is ON or OFF, and 33 is an output routine that lights up the fuel lamp 23a. 34 is a refueling remaining amount time calculation routine that is equipped with a counter that subtracts or adds each time it passes, and considers the counter value as the remaining amount of refueling.
In step 5, it is determined whether or not the remaining amount of refueling time is counting up. 36 is a refueling time initial setting routine that always returns the counter value in the refueling remaining amount time calculation routine 34 to its initial value.

With the above flow configuration, when the operation switch 13 is closed, the microcomputer 14a starts operating, preheating,
Combustion begins after pre-purge. preheat,
During pre-purging, the oil float check subroutine 28 checks the status of the contact 25a of the float 25, so if the contact 25a turns OFF, the operation is stopped at 28b without starting combustion, and the reset lamp 23b is turned on at 28c. Turn it on. On the other hand, when combustion starts, normally 31 → 32
→ 36 → 31 are drawn as a loop, so the counter for the remaining refueling time is always initialized in the refueling initial setting routine 36, but the contact 25a of the float 25 is closed due to kerosene consumption due to combustion.
When OFF, it is detected by the judgment routine of 32, and 3
The flow changes to No. 3, the refueling lamp 23a lighting routine. 33 → 34 → 3 unless kerosene is refueled
5 → 31 → 32 → 33, the counter value is added or subtracted each time it passes through the remaining refueling time calculation routine at 34, and when it reaches a predetermined value, it is determined at 35 that the time has elapsed. te37
The flow changes to the combustion stop routine.

As mentioned above, during combustion, the contact 25 of the float 25
In addition to the routine that checks the status of a, a routine that checks the status of the contact 25a of the float 25 during preheating and pre-purge, which is the preparatory stage before combustion, can be provided to check the status of the refueling point 25a when refueling is detected only during combustion. It is possible to calculate the amount of time and stop combustion after a certain period of time.

Effects of the Invention As is clear from the above description of the embodiments, according to the present invention, the amount of kerosene remaining in the tank can be accurately determined. Unexpected gas generation due to cuts,
This has the effect of eliminating problems such as odor.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a general combustion appliance, Fig. 2 is an enlarged sectional view of the tank section, Fig. 3 is a control circuit diagram of the combustion appliance according to an embodiment of the present invention, and Fig. 4 is a diagram of the microcomputer. The flowchart, FIG. 5, is a control circuit diagram of a conventional example. 3...tank, 4...burner, 10...float switch, 14a...microcomputer,
15a...Control circuit, 23a...Refueling lamp.

Claims (1)

[Claims] 1 A tank that stores oil, a burner that supplies and burns the oil, a float switch that detects the oil level height in the tank, and an operation signal of the float switch that is input to determine the oil level height in the tank. A control circuit that stops combustion after a certain period of time based on an operating signal indicating that the oil level is below a predetermined value, and stops combustion when an operating signal that indicates that the oil level in the tank is below a predetermined value during non-combustion. A combustion appliance consisting of.