JPH01252818A - Combustion amount detecting device for liquid fuel burner - Google Patents

Abstract

PURPOSE:To enable the detection of an accurate combustion amount of a device equipped with no fuel pump, by providing a fuel measuring part to compute a remaining amount of fuel by means of a signal outputted from a weight sensor to measure the weight of a fuel tank and a controller containing a fuel amount computing part to compute a combustion amount of a burner by means of a change in a signal outputted from the fuel measuring part. CONSTITUTION:A weight sensor 19 is mounted to a base plate 1 located below a fixed tank 2, and measures the weight of the fixed tank 2 having a free end (c) and a cartridge tank 7. A fuel amount is computed by a fuel measuring part 21 of a controller 20 from the weight by means of a signal outputted from the weight sensor unit 19, and a signal is outputted to a combustion amount computing part 22 and a remaining time computing part 23. When a burner 14 effects combustion at a specified combustion rate, the remaining fuel determined by a fuel measuring part 21 is gradually decreased. From the degree of the decrease, a combustion amount of a burner 14 is determined. The remaining time computing part 23 computes the remaining time (hours) when the fuel tank reaches an emptied state, and when a remaining combustion time is reduced to a value lower than a specified value, a control signal announcing the necessity for a fuel refilling and the stop of a combustion is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a means for detecting the actual combustion amount of a combustion appliance that burns liquid fuel, such as a kerosene stove or a kerosene fan heater.

BACKGROUND OF THE INVENTION Conventionally, this type of liquid fuel combustor, taking a petroleum fan heater as an example, has been mainly constructed as shown in Japanese Utility Model Application Publication No. 62-93557. A conventional configuration will be explained with reference to FIG. FIG. 6 shows the structure of the fuel tank section of the kerosene fan heater, in which a fixed tank 2 is fixed to a base plate 1 constituting the box of the combustor by means of holding fittings 3.4. The fuel in the fixed tank 2 is sucked up by a fuel pump 5, and is supplied from a vibro to a burner (not shown) where it is combusted.

A removable cartridge tank 7 is attached to the fixed tank 2 and supplies fuel to the fixed tank 2.

The lower part of the cartridge tank 7 has a fuel filler port 8 and a fuel filler cap 9, and the fuel filler cap 9 usually has a closing cap that is biased by a spring (not shown) to prevent fuel from leaking outside. 1o is provided.

This cartridge tank 7 has a plate portion 1 that receives the fixed tank 2.
At this time, the closing lid 1o is pushed up by a bottle (not shown) provided in the saucer portion 11, and the fuel inside the cartridge tank is injected into the fixed tank 2. At this time, when the tip of the fuel filler cap 9 is higher than the liquid level a of the fuel in the fixed tank 2, air flows into the cartridge tank 7 through the filler port 8, and that amount of fuel flows out into the fixed tank 2. If the tip of the fuel filler cap 9 is lower than the liquid level a of the fuel in the fixed tank 2 and the fuel lower is immersed in the liquid level heat, air will not be able to flow into the cartridge tank 7. Here, since the cartridge tank 7 is sealed, no fuel flows into the fixed tank 2. With the above configuration, the liquid level 1 in the fixed tank 2 can be maintained at a substantially constant level because the amount of fuel consumed by the burner is refilled.

Here, when the fuel in the cartridge tank 7 runs out, the liquid level in the fixed tank 2 decreases, and the burner starts abnormal combustion just before the fuel in the fixed tank 2 runs out, so combustion must be stopped before this happens.

For this purpose, a liquid level switch 12 is provided to detect the liquid level of the fixed tank 2. The liquid level switch 12 generally controls the movement of a magnetized float 13 using a reed switch (not shown).
It is configured to detect when the fuel in the cartridge tank 7 has run out based on the on/off signal of the reed switch, and from this point on, it displays and notifies you, and also drives a timer to start combustion before the fuel in the fixed tank 2 runs out. controlled to stop.

With the above configuration, the current combustion amount of the burner is estimated based on the drive amount of the fuel pump 5 that supplies fuel to the burner, and is used as a display or other control signal. In addition, some systems calculate and notify how many hours the device can continue to burn based on the amount of combustion and the usage time of the device.

Problems to be Solved by the Invention However, in the conventional configuration described above, since the amount of combustion is estimated from the amount of drive of the fuel pump, the value may deviate from the actual amount of combustion. For example, there are many variables such as pump variations, fuel passage resistance, dirt clogging, and differences in fuel viscosity due to temperature, so it is not possible to determine the exact amount of combustion.

Furthermore, it was impossible to detect the amount burned in devices that did not have a fuel pump, such as wick-type kerosene stoves.

Means for Solving the Problems In order to solve the above problems, the combustion amount detection device for a liquid fuel combustor of the present invention is provided with a weight sensor that measures the weight of a fuel tank of a burner that burns liquid fuel, The controller includes a fuel measuring section that calculates the remaining amount of fuel based on the signal from the weight sensor, and a combustion amount calculation section that calculates the burner combustion amount based on changes in the signal per unit time of the fuel measuring section. .

Function The above-described configuration works by measuring the degree of decrease in fuel in the fuel tank due to combustion in the burner using the weight sensor, and calculating the amount of combustion in the burner from this value.

Embodiments Hereinafter, embodiments of the present invention will be explained using FIGS. 1 to 5. In the drawings, parts that operate in the same way as the parts explained in FIG. 6 are designated by the same numbers.

In FIG. 1, the burner 14 transfers fuel sucked up by capillary action into a wick 15 immersed in a fixed tank 2 into a combustion tube.
This will be explained using an example of a wick type stove that burns in a gap of 6.17. The structure for attaching the cartridge tank 7 to the fixed tank 2 is the same as that shown in FIG. 6, so the explanation here will be omitted.

The fixed tank 2 is held at one end by a fulcrum metal fitting 18 in such a manner that the free end C can swing around the fulcrum. Furthermore, the free end 0 is held by a holding fitting 3 to prevent the fixed tank 2 from moving more than necessary.

The cartridge tank 7 is attached to the free end C side of the fixed tank 2. A weight sensor unit 19 is attached to the base plate 1 at the bottom of the fixed tank 2 at a position opposite to this, and the cartridge tank 7 is attached to the free end C side of the fixed tank 2. Measure the weight of tank 7.

The fuel amount is calculated based on the weight of the signal from the weight sensor unit 19 by the fuel measuring section 21 of the controller 20, and the signal is output to the combustion amount calculating section 22 and the remaining time calculating section 23. Reference numeral 24 indicates a timer that determines the measurement time width of the combustion amount calculation section 22, which will be explained later. The values calculated by the combustion amount calculating section 22 and the remaining time calculating section 23 are outputted to the display section 25 and an alarm (not shown). Also, if necessary, the fuel remaining in the fixed tank 2 may be reduced. The structure may be such that the combustion of the burner is stopped at certain times.

An example of the configuration of the weight sensor unit 19 is shown in FIG.

Here, an example will be described in which a capacitive sensor is used as the weight sensor 26. This has a structure in which two ceramic plates 29 and 30 having electrodes 27 and 28 on their inner surfaces are opposed to each other with a constant gap maintained by a spacer 31. The lower ceramic plate 30 is attached to the base plate 1 and has an air circulation hole 32 in the center. Also, a lead wire 33 is connected from each electrode.
．． 34 is pulled out. Further, a pressure receiving pin 35 is attached to the center of the upper ceramic plate 29. The weight sensor 26 utilizes the fact that when a weight is applied to the pressure receiving pin 35, the ceramic plate 29 is bent, the gap between the upper and lower electrodes changes, and the capacitance changes.

The pressure receiving pin 35 is in contact with the center of a buffering leaf spring 3 whose both ends are held by a pressure receiving body 36 arranged so that its upper side is in contact with the fixed tank 2, thereby transmitting the weight of the tank to the sensor 26. There is. Further, the gap d between the lower end of the pressure receiving body 36 and the base plate 1 prevents abnormal force or impact from being applied to the weight sensor 26.

FIG. 3 shows an example of a sensor signal detection circuit in the fuel measuring section 21. Here, an astable multivibrator is constructed using a comparator 38 with a generally known two-way open collector output. In this circuit, the charging/discharging time to the sensor 26 changes through the resistor 39 depending on the capacitance of the sensor 26, and the output EO is a rectangular wave having a frequency inversely proportional to the capacitance of the sensor 26. In the figure, 40 is a DC power supply,
41.42 is a voltage dividing resistor for obtaining the reference potential Es, 43
is a positive feedback resistor of comparator a8, and 44 is a pull-up resistor of comparator 38, which is an open collector output.

The fuel measuring section 21 measures the frequency f of the output Eo using a microcomputer or the like (not shown), and calculates the amount of fuel, residual twisting time, etc. FIG. 4 shows the relationship between weight W and frequency f. As the weight W of the sensor 26 increases, the capacitance also increases, and therefore the frequency f decreases. Here, frequency f indicates the frequency when the cartridge tank 7 is removed from the fixed tank 2, and f indicates the frequency when the empty cartridge tank 7 is attached. Furthermore, when the cartridge tank 7 is full of fuel, the pressure receiving body 36 contacts the base plate 1 (the gap d disappears), so the frequency f□ bends without becoming the characteristic shown by the broken line. Therefore, the weight changes from Wm to Wo.
The amount of remaining oil is calculated based on the amount of change f in the frequency between.

Now, if the burner 14 burns at a certain combustion amount, that amount of fuel will be consumed. Therefore, the remaining fuel determined by the fuel measuring section 21 decreases moment by moment.

The combustion amount of the burner 14 can be determined from this degree of decrease.

The combustion amount calculation unit 22 uses the reference time ΔT obtained by the timer 24.
This is a part that calculates the current combustion amount Q of the burner 14 from the amount of fuel that decreases during this period.

The remaining time calculation unit 23 calculates how many hours it will take for the fuel to run out if the burner is burned at the current burner combustion amount based on the combustion amount calculated by the combustion amount calculation unit 22 and the remaining fuel amount calculated by the fuel measurement unit 21. . The outputs of these calculation units 22 and 23 are used to display the current combustion amount in a par graph or digitally display the remaining combustion time on the display unit 25. In addition to displaying information, it can also be used for various control signals as needed, such as notifying refueling when the remaining combustion time falls below a certain value, or stopping combustion to prevent abnormal combustion.

FIG. 5 shows a flowchart when the controller 20 is configured with a microcomputer (not shown). In the diagram, flows that perform the same operations as those in FIG. 1 are indicated by the same numbers.

The fuel measuring section 21 shown in FIG. 5 receives the signal from the weight sensor 2θ, calculates the weight W of the remaining fuel from the characteristics shown in FIG. 4, and stores it. At the initial stage of energization, the timer 24 is not yet operating, so the timer-up determination unit 45 determines "N".
Take the route. Similarly, the timer count determination unit 46 also outputs “N”.
The current fuel amount W is stored as the initial fuel amount W1 in the W1 storage section 47 through the path of ``Determination I''. Then timer 2
Operate 4.

At this point, since the combustion amount has not yet been calculated, the residual combustion amount calculation section 23 and the residual combustion time display section 25b do not operate, and the fuel is returned to the fuel measurement section 21 via the path plane.

Thereafter, until the timer 24 measures the predetermined time ΔT, the fuel amount is measured by the fuel measuring unit 21 while the I
Loop the routes of ,■,■. When time 6 has elapsed, the time-up determination section 45 makes a "Y" determination, and the timer 24 is reset, and the W2 storage section 48 stores the output W of the fuel measurement section 21 at that time as W2. After that, the combustion amount calculation unit 22 calculates the combustion amount Q of the burner 14 from the values of Wl and W2.
Calculate. This arithmetic expression is expressed by the following equation, assuming that the timer time Δt is 1 minute and the fuel is white kerosene.

Q=QO,X60X (W2-Wl) (kca
1j/h) Here, 60X (W2-Wl) is the fuel consumption per hour (!I), and GO is the calorific value of white kerosene (1o, 3
kcall/a).

The current combustion amount Q of the burner 14 determined by the combustion amount calculation section 22 is displayed on the display section 25m, and is used as a guide for the user's calorie adjustment. Moreover, it is also possible to easily realize the use of this signal for room temperature control.

Thereafter, since the timer has stopped, the timer count determination unit 46 determines that u N 11, and the process moves to the W1 storage unit 47 again to repeat the above operations.

When the current combustion amount Q of the burner 14 is calculated by the combustion amount calculating section 22, the remaining combustion time calculating section 2 calculates the current combustion amount Q of the burner 14 from the residual combustion W and the combustion amount Q.
3 calculates the remaining burn time X.

This remaining combustion time X is calculated using the following equation.

X= ((W-WT)XQO)/Q (h) Here, WT is the weight of the fuel tank, and the true weight of the fuel is determined by (W-WT).

Thereafter, the remaining combustion time is displayed on the remaining combustion time display section 25b.

In addition to displaying information, this signal can also be used to notify when the fuel in the tank is running low and to automatically shut down the vehicle.

The remaining combustion time X obtained here is the time when the current combustion amount Q is continued, and if the combustion amount Q is varied, the time X is automatically corrected.

If the controller 20 is realized by a microcomputer as in the above embodiment, the remaining combustion time calculation section 23 will be configured only for program processing, and no addition or modification of parts will be required, resulting in a simple configuration and an increase in cost. This has the effect that the remaining combustion time X can be measured accurately with almost no residual combustion time.

Here, the remaining combustion time calculating section 23 is not provided, and the fuel measuring section 21
It may be configured to display or notify that the fuel is out of fuel when the signal becomes below a certain value.

The weight sensor 26 may have a structure other than the capacitance type explained in FIG. 2, and may also use a strain gauge or a structure based on another principle.

Further, in this specification, a microcomputer is used for the controller 2o, but the present invention is not limited to this.

Furthermore, although the embodiments have been described using a wick-type kerosene stove as an example, the same effects can be obtained even if the present invention is applied to devices that use the fuel pump 5, such as kerosene fan heaters and hot air heaters. .

Effects of the Invention The combustion amount detection device for a liquid fuel combustor of the present invention described above has the following various effects.

(1) Since the weight sensor constantly measures the amount of fuel in the tank and calculates the burner combustion amount, the true combustion amount is always accurately determined without being affected by temperature or component variations.

(2) Similarly, the amount of combustion can be measured even in a combustor that does not have an actuator such as a fuel pump, such as a natural vaporization kerosene stove that uses a wick.

(3) Since the configuration is such that only a weight sensor is added as a sensor, the overall system configuration is simple and there are few failures.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of the main parts of a combustion amount detection device for a liquid fuel combustor according to an embodiment of the present invention, FIG. 2 is a configuration diagram showing an example of a weight sensor section, and FIG. 3 is a configuration example of a sensor detection circuit. circuit diagram,
FIG. 4 is a detection characteristic diagram of the weight sensor of FIG. 2, FIG. 5 is a flowchart explaining the operation of the controller 20, and FIG. 6 is a configuration diagram of a conventional combustor. 2. Fixed tank (fuel tank), 7... Cartridge tank (fuel tank), 14... Burner, 19... Weight sensor unit (weight sensor),
2o...Controller, 21...Fuel measurement section, 22...Combustion amount calculation section, 23...Remaining time calculation section, Q...Burner combustion amount, W・・・・・・
Remaining amount of fuel, X...Remaining burning time of burner, ΔT...Unit time. Name of agent: Patent attorney Toshi Nakao, Baka 1, No. 2
Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) a fuel measuring section that includes a burner that burns liquid fuel contained in a fuel tank and a weight sensor that measures the weight of the fuel tank, and that calculates the remaining amount of fuel based on a signal from the weight sensor; A combustion amount detection device for a liquid fuel combustor, comprising a controller including a combustion amount calculating section that calculates the combustion amount of the burner based on a change in a signal per unit time of a fuel measuring section. (2) The controller is configured to include a remaining time calculation section that calculates the remaining combustion time of the burner from the combustion amount signal from the combustion amount calculation section and the remaining amount of fuel from the fuel measurement section. Combustion amount detection device for liquid fuel combustor.