JPH09112901A - Liquid fuel supplying apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate highly accurate measurement of the amount of a liquid fuel supplied to combustion equipment. SOLUTION: In the first case where a flow rate obtained from the amount of the liquid fuel flowing as detected by a flow quantity sensor 26 is below a threshold, a control section computes an accumulation to determine a cumulative amount of the liquid fuel supplied corresponding to the flow quantity obtained from a drop in liquid level detected by a float switch 18 as liquid level sensor.

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 for supplying liquid fuel to combustion equipment such as a heater and a water heater.

[0002]

2. Description of the Related Art A liquid fuel supply apparatus of this type disclosed in Japanese Utility Model Publication No. 7-11321 discloses a main tank for storing a large amount of liquid fuel such as petroleum (for example, for one housing complex). (One is installed on the ground surface near the building),
It is installed between one or more combustion devices (for example, installed for each household in the ridge of an apartment house). Then, the liquid fuel in the main tank is sucked up to a predetermined height (for example, about the second floor of the housing complex), and the liquid fuel is supplied to the combustion equipment located at a position lower than the liquid fuel supply device. Such a liquid fuel supply device generally has a storage tank for temporarily storing the liquid fuel, a pump for sucking the liquid fuel into the storage tank, and a liquid level for detecting the liquid level of the liquid fuel in the storage tank. It is equipped with a float switch as a sensor and a control unit for controlling the operation of the pump. Then, based on the detection signal of the float switch, the operation of the pump is controlled so that the liquid level in the storage tank is located within a predetermined range.

By the way, in general, a single main tank is shared by a plurality of households, so it is necessary to calculate a fuel usage fee for each household. Therefore, it is necessary to measure the supply amount of liquid fuel for each household, that is, the cumulative supply amount of liquid fuel from each liquid fuel supply device to the combustion equipment. In the conventional liquid equipment including the above-described example, at least the amount of liquid fuel flowing between the liquid fuel supply apparatus and the combustion equipment, that is, the outlet side of the storage tank of the liquid fuel supply apparatus is detected. A flow meter is installed to measure the cumulative supply of liquid fuel. This flow rate meter generally has a flow rate sensor structure such as an oval gear type or a film type. still,
In this specification, the amount of liquid fuel flowing does not include a time parameter. On the other hand, the flow rate is the amount that flows per unit time.

[0004]

The flow rate sensor structure of the flow rate meter used for measuring the cumulative supply amount of the liquid fuel supply apparatus described above has relatively high accuracy when the flow rate is larger than a certain value. Although it can be weighed, the fact is that the accuracy is extremely low below that value. Moreover, when measuring the cumulative supply amount using such a flow meter,
Needless to say, the measurement result is not suitable for practical use because the value including the measurement error accumulates as the flow rate is frequently below a certain value or continues for a long time. FIG.
Experimental results of an experiment for obtaining a measurement error according to the flow rate of the liquid with respect to an example of the conventional flow meter described above will be shown. Referring to FIG. 6, it can be seen that in the flow rate meter used in this experiment, a metering error is generated to a degree unfavorable for practical use in a flow rate range of 3 ml / min or less.

An object of the present invention is to provide a liquid fuel supply apparatus capable of measuring the supply amount of liquid fuel to a combustion device with high accuracy.

[0006]

According to the present invention, the following aspects (1) to (4) can be obtained.

(1) A storage tank capable of temporarily storing the liquid fuel pumped from an external main tank, a pump for pumping the liquid fuel into the storage tank, and a liquid fuel pump in the storage tank. A liquid level sensor that detects at least two levels of liquid level, a control unit that controls the operation of the pump based on a detection signal of the liquid level sensor, and a liquid fuel outlet of the storage tank, which is provided on the outlet side.
In a liquid fuel supply device having a flow rate sensor for detecting the flow rate of the liquid fuel on the outlet side, and a display section for displaying the cumulative supply amount of the liquid fuel flowing out from the storage tank and supplied to a combustion device. In the first case in which the flow rate obtained based on the circulating amount of the liquid fuel detected by the circulating amount sensor is equal to or less than a predetermined threshold value, the control unit determines the liquid level detected by the liquid level sensor. A liquid fuel supply apparatus, characterized in that a distribution amount obtained based on a decrease is cumulatively calculated as a cumulative supply amount of liquid fuel.

(2) In the second case, the control unit obtains the flow rate sensor when the flow rate obtained based on the flow rate detected by the flow rate sensor is larger than a predetermined threshold value. The liquid fuel supply apparatus according to the aspect (1), in which the distribution amount is cumulatively calculated as the cumulative supply amount of the liquid fuel.

(3) The control unit also detects whether or not the pump is operating, and while the pump is operating, cumulatively calculates the flow rate obtained by the flow rate sensor as the cumulative supply amount of liquid fuel. The liquid fuel supply apparatus according to aspect (1) or (2).

(4) The control unit includes a distribution amount data storage unit that stores the distribution amount obtained by the distribution amount sensor in the first case as distribution amount data, and in the first case, When the liquid does not continue for a period longer than the period required for lowering the liquid level, the distribution amount data for the period in which the first case continues is cumulatively calculated as the cumulative supply amount of the liquid fuel, and the liquid according to any one of the aspects (1) to (3) Fuel supply device.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A liquid fuel supply apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

1, 2, and 3 are vertical sectional views of a liquid fuel supply apparatus according to Embodiment 1 of the present invention, respectively.
It is an expanded longitudinal cross-sectional view of the float switch of FIG. 1, and a block diagram of a control apparatus.

First, the structure of the liquid fuel supply apparatus will be described with reference to FIGS. 1 and 2, the present apparatus comprises a storage tank 1 capable of temporarily storing liquid fuel pumped from an external main tank (not shown), a pump 3 for pumping liquid fuel into the storage tank 1, and a storage Float switch (switch S as a liquid level sensor for detecting the liquid level of the liquid fuel in the tank 1
1 to S3) 18 and a control unit (not shown in FIGS. 1 and 2) that controls the operation of the pump 3 based on the detection signal of the float switch 18.

In particular, in the present invention, the control unit also performs a process of calculating the cumulative supply amount of the liquid fuel and displaying the calculation result on the display unit which will be described later, as described in detail later.

The storage tank 1 has a hollow rectangular shape, and the bottom surface thereof has an inlet 1 connected to the main tank.
a and an outlet 1b connected to a combustion device (not shown). A flow rate sensor 26 that detects at least the flow rate of the liquid fuel flowing from the storage tank 1 through the flow outlet 1b is provided on the flow outlet 1b side. The structure of the mechanical portion of the flow rate sensor 26 is, for example, the oval gear type or the film type described above. The distribution sensor 26 is also electrically connected to the control unit,
A pulsed electric signal indicating the flow rate (for example, a pulse signal in which one pulse indicates the flow of 1 milliliter of liquid fuel)
Is output to the control unit as a detection signal.
It should be noted that, in order to prevent impurities contained in the liquid fuel flowing out from entering the mechanical portion of the flow rate sensor 26 and causing the sensor to malfunction on the upstream side of the outlet 1b, dust, etc. from the liquid fuel flowing out is prevented. A tubular outlet filter 25 for removing impurities is provided. On the other hand, on the inflow port 1a side, a control valve 24 for circulating / blocking the reverse flow of the liquid fuel is provided by the control of the control unit based on a predetermined condition. A filter chamber 2 is interposed between the inflow port 1a and the storage chamber 1d, and a filter 2a for removing impurities such as dust from the liquid fuel flowing in from the inflow port 1a can be replaced in the filter chamber 2. It is located in.

The pump 3 is a rotary suction pump arranged in the upper opening of the filter chamber 2 so as to close the opening. The pump 3 faces the filter chamber 2 on the inflow side where the check valve 4 is connected. In addition, the outflow side and the rotating shaft 3a are connected to the storage chamber 1
facing d.

The motor 5 is fixed to the upper surface of the storage tank 1 coaxially with the pump 3 via a rubber-made fixing base 6, and its shaft 5a projects into the storage chamber 1d and connects the connecting shaft 7 to it. It is connected to the rotating shaft 3a of the pump 3 via the. More specifically, insertion slits are formed at the ends of the shaft 5a and the rotary shaft 3a, and the ends of the connection shaft 7 are inserted into the slits for connection.

The oil cup 8 is erected on the inner bottom surface of the storage chamber 1d so as to surround the pump 3 and has a cylindrical shape. The priming chamber 9 is provided on the inner bottom surface of the storage chamber 1d so as to project adjacent to the oil cup 8 and has a cylindrical shape. The oil cup 8 and the priming chamber 9 include side plates for preventing leakage, In addition, they are communicated with each other by the inclined passage 10 having a predetermined bottom height.

The liquid outlet float 11 is arranged in the priming chamber 9 and has a cylindrical shape. The shaft 11a connected to the priming liquid discharge float 11 projects from the upper surface of the storage tank 1, and a spring 11c stretched between the operation button 11b fixed to the projecting end and the upper surface of the storage tank 1. Is biased upward by. The priming liquid deriving float 11 is used when the pump 3 is operated in a state where the liquid fuel is exhausted in the storage chamber 1d.
By pushing 1 into the priming chamber 9, the liquid fuel stored in the priming chamber 9 can be introduced into the oil cup 8 through the inclined passage 10.

The outflow chamber 13 is erected on the inner bottom surface of the storage chamber 1d so as to surround the upper opening of the outflow port 1b, and has a cylindrical shape. In the outflow chamber 13, an outflow valve 14 capable of opening and closing the upper opening of the outflow port 1b is arranged. The outflow valve 14 has a shaft 14 a connected to the outflow valve 14 slidably inserted into a holder 15 fixed to the upper surface of the storage tank 1 and protrudes from the holder 15. Further, the projecting end of the shaft 14a can be pulled upward from the position shown in the drawing so as to engage with the holder 15, and in this engaged state, the outflow valve 14 is opened and the liquid fuel in the storage chamber 1d is discharged from the outlet 1b. Can be drained from. The outflow chamber 13
A filter 25 having a tubular shape is provided on the top.
The filter 25 prevents a failure of the sensor structure portion caused by dust contained in the liquid fuel entering the circulation amount sensor 26.

Float switch 18 as a liquid level sensor
Is vertically provided on the inner upper surface of the storage chamber 1d. The float switch 18 is fitted with a vertically long cylindrical float tube 18a and an outside of the float tube 18a so as to be vertically movable.
It is composed of a ring-shaped float 18b whose downward movement is restricted by a stopper 18d. A magnet 18c is built in the float 18b. Also, float tube 1
In the inside of 8a, a total of three reed switches S are turned on by the proximity of the magnet 18c and turned off by the separation.
1, S2, and S3 are arranged.

The float switch 18 will be described in detail with reference to FIG. At the lowermost portion of the float tube 18a, a reed switch S1 for detecting the lower limit liquid level L1 that is turned on when the float 18b is in contact with the stopper 18d is arranged. A reed switch S2 that detects the upper limit liquid level L2 is arranged above the reed switch S1. Further, a reed switch S3 for detecting the excess liquid level L3 is arranged above the reed switch S2. Further, the reed switch S1 and the reed switch S2 are arranged at a predetermined interval so that the detection areas ST1 and ST2 do not overlap each other. Further, the reed switch S2 and the reed switch S3 are arranged such that the detection regions ST2 and ST3 of the reed switch S2 partially overlap each other.

The control board case 17 is a control board case arranged on the upper surface of the storage tank 1. On the surface of the control board case 17, it is possible to selectively display the liquid crystal display plate 22a as a display unit for displaying the cumulative supply amount of the liquid fuel, the operating state of the pump 3 and the liquid level position in the storage chamber 1d. Other display units and the like are provided.

Next, the control system of the liquid fuel supply system will be described with reference to FIG. In FIG. 3, the control unit 20 is composed of, for example, a microcomputer, and a power switch SW, reed switches S1, S2, and S3, which are components of the float switch, and a circulation amount sensor 26 are connected to the input side thereof. Has been done. A liquid crystal display panel 22a, a control valve 24, and a drive circuit 21 that supplies drive power to the pump driving motor 5 are connected to the output side. The control unit 20 also stores a distribution amount stack data storage unit 20 for temporarily storing distribution amount stack data described later by the distribution amount sensor 26.
1 is provided.

In the control section 20, based on the open / close signal of the power switch SW, the detection signal of the flow rate sensor 26, and the detection signals of the reed switches S1, S2, and S3,
According to the program stored in the memory, the liquid crystal display panel 2
2a display control, actuation of control valve 24, and pump 3
Controls the operation of.

Next, the operation of this liquid fuel supply system will be described.

First, the basic operation of the present liquid fuel supply apparatus, that is, the operation of pumping the liquid fuel into the storage tank 1 will be described. In the present liquid fuel supply device, the control unit 20 controls the operation of the pump 3 based on the detection signal of the float switch 18 as a liquid level sensor. When the reed switch S1 of the float switch 18 is on, the control unit 20 drives and controls the pump 3 (motor 5) so as to pump the liquid fuel into the storage chamber 1d. After that, if either the reed switch S2 or S3 is turned on, the storage room 1
When it is determined that the liquid level in d has reached the upper level, the operation of the pump 3 is stopped and the pumping of the liquid fuel is interrupted. Pump 3
After the operation of is stopped, the reed switch S1 is checked, and the liquid level in the storage chamber 1d is lowered by the supply of the liquid fuel to the combustion device, and the reed switch S1 is in a standby state until the reed switch S1 is turned on. Become. When the reed switch S1 is turned on, it is determined that the liquid level in the storage chamber 1d has reached the lower limit, and the pump 3 is operated. After that, the above steps are repeated.

FIG. 4 shows the relationship between the capacity of the storage tank 1 (storage tank 1c) shown in FIG. 1 and the float switch 18. In FIG. 4, in the storage tank 1, for example, when the reed switch S1 is turned on (low level) to the reed switch S2 is turned on (high level) (displacement amount = D), a diagonal line in the figure The liquid fuel of the indicated capacity P will be pumped up. Conversely, if the liquid fuel is supplied from the state where the reed switch S2 is turned on to the state where the reed switch S1 is turned on, the supply amount is P. Here, in the present embodiment, the storage tank 1 is designed so that the capacity P is 300 ml.

Next, the calculation and display operation of the cumulative supply amount of liquid fuel in the present liquid fuel supply device will be described with reference to the flow chart of FIG.

The flow of the calculation and display operation of the cumulative supply amount of liquid fuel in the present liquid fuel supply device is as follows.
To the basic flow (such as the pump operation control described above) in accordance with a detection signal (a pulse signal indicating that 1 pulse of liquid fuel flows 1 pulse) from the flow rate sensor 26 connected to the control unit 20. Format. That is, the control unit 20 processes the following flow every time 1 milliliter of liquid fuel is supplied from this device.

Now, in step Sf11, the control unit 20
Starts the timer for 1 minute and if 1 minute has not elapsed, the number of pulses of the detection signal of the flow rate sensor 26 is counted by the pulse counter for 1 minute in step Sf12, and the process proceeds to step Sf21 while 1 minute has elapsed. If so, the process proceeds to step Sf13. In step Sf13, the flow rate V
The pulse number for 1 minute in step Sf12 is substituted into f [milliliter / minute], the pulse counter for 1 minute is reset in step Sf14, the timer for 1 minute is reset in step Sf15, and the process proceeds to step Sf21. That is, the control unit 20 counts the number of pulses per minute, sets this as the flow rate Vf, and rewrites this value every minute.

Next, the control unit 20 detects whether or not the pump 3 is operating in step Sf21, and if it is operating, determines in step Sf22 which measurement mode was used before the pump 3 was operating. . Step Sf22
If it is determined in [Distribution amount sensor measurement mode], the process proceeds to step Sf31, while if it is [liquid level sensor measurement mode], the process proceeds to step Sf23. In step Sf23, the above-mentioned capacity P is added to the cumulative supply amount.
Is added, and the measurement mode is set to [circulation amount sensor measurement mode] in step Sf24. On the other hand, if the pump 3 is not operating in step Sf21, it is determined in step Sf25 whether or not it is the first time that the pump 3 has changed from the operating state to the non-operating state. If it is the first time, the process proceeds to step Sf26. If it is the second time or more, the process proceeds to the above step Sf31. In step Sf26, it is determined whether or not the flow rate Vf is 3 ml / min or less. If it is 3 ml / min or less, the process proceeds to step Sf27, while if it is greater than 3 ml / min, the above-mentioned step Sf24 is performed.
Move to. In step Sf27, the measurement mode is set to the [liquid level sensor measurement mode], and in step Sf28, the data in the flow rate stack data storage unit 201 in the control unit 20 is reset.

Subsequently, the control section 20 carries out step Sf31.
Determine the measurement mode with [Distribution amount sensor measurement mode]
If so, the process proceeds to step Sf32, while if the [liquid level sensor measurement mode], the process proceeds to step Sf33. In step Sf32, one pulse of the detection signal of the circulation amount sensor 26 is added to the cumulative supply amount, and the process proceeds to step Sf50. On the other hand, in step Sf33, one pulse is added to the data in the circulation amount stack data storage unit 201, and the process proceeds to step Sf41.

Next, the control unit 20 determines in step Sf41 whether the flow rate Vf is 3 ml / min or less, and if it is 3 ml / min or less, step Sf5.
On the other hand, if it is greater than 3 ml / min, the process proceeds to step Sf42. In step Sf42, the distribution amount stack data stored in the distribution amount stack data storage unit 201 is added to the accumulated supply amount, and step Sf
Move to 43. In step Sf43, the measurement mode is set to [circulation amount sensor measurement mode], and the process proceeds to step Sf50.

In step Sf50, the controller 20 displays the cumulatively calculated cumulative supply amount of the liquid fuel on the liquid crystal display plate 22a. After that, the control unit 20 repeats the steps described above according to the pulse signal from the circulation amount sensor 26.

As described above, in the liquid fuel supply device according to the present invention, the flow rate of the liquid fuel is below a predetermined value,
When the detection error of the flow rate sensor is large, the accumulated supply amount of the liquid fuel to the combustion equipment is highly accurate because the accumulated supply amount is cumulatively calculated using the liquid level sensor that does not cause such an error as much as possible. Can be measured.

In this embodiment, the measurement mode is switched when the pump 3 is not in operation ([liquid level sensor measurement mode],
Alternatively, the [flow rate sensor measurement mode]) is set according to the flow rate Vf (step Sf26), but the present invention is not limited to this, and the liquid level sensor from a high level to a low level can be used. The measurement mode may be switched according to the time required for the decrease in the position.

[0038]

According to the liquid fuel supply apparatus of the present invention, when the flow rate obtained by the control unit based on the circulating amount of the liquid fuel detected by the circulating amount sensor is equal to or lower than a predetermined threshold value, The cumulative amount of liquid fuel that is obtained based on the drop in the liquid level detected by the position sensor is cumulatively calculated, so it is possible to compensate for the detection error of the liquid amount sensor when the flow rate is small, and the cumulative amount of liquid fuel is supplied. The amount can be measured with high accuracy.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a float switch in the apparatus shown in FIG.

FIG. 3 is a diagram showing a control system included in the device shown in FIG.

FIG. 4 is a diagram for explaining the relationship between the liquid level drop and the supply amount of the liquid fuel in the device shown in FIG.

5 is a flow chart showing a calculation and display operation processing of a cumulative supply amount of liquid fuel in the apparatus shown in FIG.

FIG. 6 is a diagram showing an example of the above conventional flow rate meter.
The experimental result of the experiment which obtains the measurement error according to the flow rate is shown.

[Explanation of symbols]

 1 Storage Tank 1a Inlet 1b Outlet 1c Return Outlet 1d Storage Chamber 3 Pump 18 Float Switch 20 Control Unit 22a Liquid Crystal Display Panel 24 Control Valve 25 Outlet Filter 26 Flow Rate Sensor 201 Flow Rate Stack Data Storage S1 to S3 Lead switch

Claims (4)

[Claims] 1. A storage tank capable of temporarily storing liquid fuel pumped from an externally provided main tank, a pump for pumping liquid fuel into the storage tank, and at least liquid fuel in the storage tank. A liquid level sensor that detects a two-level liquid level, a control unit that controls the operation of the pump based on a detection signal of the liquid level sensor, and a liquid fuel outlet port of the storage tank,
In a liquid fuel supply device having a flow rate sensor for detecting the flow rate of the liquid fuel on the outlet side, and a display section for displaying the cumulative supply amount of the liquid fuel flowing out from the storage tank and supplied to a combustion device. In the first case in which the flow rate obtained based on the circulating amount of the liquid fuel detected by the circulating amount sensor is equal to or less than a predetermined threshold value, the control unit determines the liquid level detected by the liquid level sensor. A liquid fuel supply apparatus, characterized in that a distribution amount obtained based on a decrease is cumulatively calculated as a cumulative supply amount of liquid fuel. 2. The distribution unit obtains the distribution amount sensor when the flow rate obtained based on the distribution amount detected by the distribution amount sensor is larger than a predetermined threshold value in a second case. The liquid fuel supply apparatus according to claim 1, wherein the amount is cumulatively calculated as a cumulative supply amount of the liquid fuel. 3. The control unit also detects whether the pump is operating or not, and while the pump is operating, cumulatively calculates the flow rate obtained by the flow rate sensor as a cumulative supply amount of liquid fuel. Item 3. The liquid fuel supply device according to item 1 or 2. 4. The control unit includes a distribution amount data storage unit that stores, as distribution amount data, a distribution amount obtained by the distribution amount sensor in the first case, and in the first case, the liquid amount is stored. The liquid fuel supply according to any one of claims 1 to 3, wherein when the first case does not continue for a period longer than the period required for lowering the position, the distribution amount data for the period in which the first case continues is cumulatively calculated as the cumulative supply amount of the liquid fuel. apparatus.