JPH0894417A - Remote residual-quantity detection device - Google Patents

Abstract

PURPOSE: To provide a residual-quantity detection device, for a portable pressure container, in which an electronic component is operated normally even when a low-temperature liquefied gas is filled and by which data on a precise residual quantity can be output to the outside. CONSTITUTION: A residual-quantity detection device 5 is provided with Hall elements 22 which are arranged so as to be lined up in a sensor part 17, and it detects the position of a residual-quantity display utensil 12 which is raised and lowered so as to be interlocked with a float inside a container. Output signals from the respective Hall elements 22 are sent to a controller 18, an arithmetic operation to detect the position is performed here, and data on a residual quantity is output to the outside. A heater 25 is installed at the sensor part 17. When a sensor-part temperature detected by a thermistor 23 is at a low temperature, the heater is electrified by a signal from the controller part 18, and the sensor part 17 is held at a proper-temperature state. Thereby, electronic components in the sensor part 17 are held in a normal state, and the reliability of the data is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting the remaining amount of a fluid such as a high-pressure liquefied gas contained in a portable pressure container, and in particular, an operator or the like can easily determine the remaining amount of the fluid at the installation site of the container. As can be seen from the above, the target is a portable pressure vessel equipped with an on-site remaining amount detector, and the remaining amount display on this on-site remaining amount detector can be accurately output to a remote location such as a centralized control center. The present invention relates to a remote remaining amount detecting device.

[0002]

2. Description of the Related Art For example, in a portable pressure vessel such as a gas cylinder, a site residual quantity detector such as a meter is mounted so that an operator can easily confirm the residual fluid quantity at the installation site. As the remaining amount detector, a device that displays the remaining amount by a meter with an internal pressure value, or a float that moves up and down according to the liquid level in the pressure container, and the float and the residue provided on the container head are installed. There is one in which the remaining amount can be confirmed by the position of the display device by interlocking with the amount display device.

Further, for a portable pressure vessel equipped with a field residual quantity detector, the display information of the field residual quantity detector so that the fluid residual quantity can be confirmed at a remote location such as a central control center. An on-site / remote remaining amount detecting device which externally outputs the data and can be remotely output via a telephone line or the like is already known (Act No. 6-33380).

This device is equipped with a remaining amount sensor (magneto-resistive element) for detecting the position of the remaining amount indicator of the on-site remaining amount detector, and a sensor attachment for mounting on the on-site remaining amount detector. The position information from the sensor can be displayed at a remote place via a telephone line or the like after being converted into an electric signal and subjected to predetermined signal processing by an amplifier or the like.

[0005]

However, in such an on-site / remote residual quantity detecting device, when the fluid in the portable pressure vessel is a low temperature liquefied gas, the temperature inside the vessel may cause a pipe wall or the like. Therefore, the detection device itself is exposed to a considerably low temperature environment (subzero temperature). As a result, the electronic components inside the device may not operate accurately, and the reliability of the detected remaining amount data may be significantly impaired.

The present invention has been made in view of the above situation, and provides a remaining amount detecting device capable of accurately outputting the remaining amount data to the outside even when the fluid in the container is at a considerably low temperature. The purpose is to provide.

[0007]

In order to achieve the above object, a remote residual amount detecting device according to the present invention is mounted on a portable pressure vessel equipped with an on-site residual amount detector and is displayed on the in-situ residual amount detector. A remote remaining amount detecting device for converting the information on the remaining amount of fluid in the container into an electric signal and outputting it to the outside, the device being installed within the displacement range of the remaining amount indicator of the on-site remaining amount detector, and displaying the remaining amount. A sensor unit for detecting the current position of the tool, a signal processing unit connected to the sensor unit for converting an output signal from the sensor unit into an electric signal corresponding to the remaining amount of the fluid and externally outputting the electric signal, and a temperature of the sensor unit. And a temperature control unit for controlling the operation of the sensor unit to maintain the operation of the sensor unit in a normal state.

Further, preferably, in this remaining amount detecting device, the remaining amount indicator is made of a paramagnetic material that moves up and down inside the on-site remaining amount detector according to the liquid level in the container, and the sensor section is It has a plurality of Hall elements arranged along the ascending / descending range of the magnetic body.

More preferably, the temperature control means is configured to detect a temperature of the sensor unit, a heater arranged near the sensor unit to heat the sensor unit, and a temperature sensor which detects the temperature of the sensor unit. And a heater control unit for controlling energization of the heater.

[0010]

By controlling the temperature of the sensor part, the electronic parts of the sensor part can be maintained in a normal operating state even if the fluid filled in the container is at a considerably low temperature, and the accurate remaining amount can be maintained. You can get the data.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A remote remaining amount detecting device according to the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing a state in which a remote residual amount detecting device is further attached to a portable pressure vessel equipped with an on-site residual amount detecting device, and FIG. 2 is an upper external view thereof.
FIG. 3 is an enlarged view of a main part of the device.

In FIG. 1, reference numeral 1 denotes a portable pressure vessel (hereinafter abbreviated as a vessel) filled with a low temperature liquefied gas. The container 1 includes an inner container 2 for containing a liquefied gas F and a heat insulating space X.
The inner container 2 and the outer container 3 surrounding the inner container 2 are integrated with each other via a mouthpiece 4 provided on the upper part of the container 1.

A liquefied gas on-site residual amount detecting device 5 is attached to the upper portion of the base 4. This on-site residual amount detection device 5 is a plug member 7 that is screwed into the mouthpiece 4 via a washer 6, a hollow cylindrical body 8 that is integrated with the plug member 7 and projects upward from this, and in this cylindrical body. The operation tool 10 is mounted on the upper end of the rod 9. On the other hand, the lower end of the rod 9 extends into the inner container 2 through the base 4, and a float 11 that moves up and down inside the inner container according to the liquid level of the liquefied gas F is attached to the tip of the rod 9. .

While the tubular body 8 is made of a non-magnetic pressure-resistant material, the operating tool 10 is made of a magnet, and the outer peripheral surface of the tubular body 8 has a ring shape made of a plastic magnet (paramagnetic material). The remaining amount display tool 12 is inserted in a vertically movable manner. As a result, the operating tool 10 moves up and down inside the cylindrical body 8 as the float 11 moves up and down due to changes in the remaining amount, and the remaining amount indicator 12 moves up and down due to the magnetic coupling with the operating tool 10 to leave the remaining amount of liquefied gas in the container. Can be displayed externally.

In addition to the above-mentioned elements, the on-site remaining amount detecting device 5 is equipped with a protective cover 13 which is attached to the base 4 and covers the cylindrical body 8 and the remaining amount indicator 12.
Remaining amount display scales are formed on the two viewing windows 14 provided in No. 3 and the height position of the remaining amount display tool 12 inside thereof is visually confirmed through the viewing windows 14 so that the operator ( (Not shown) can detect the remaining amount of the liquefied gas F.

The remote remaining amount detecting device 15 according to the present invention is attached to the on-site remaining amount detecting device 5 configured as described above so as to detect the height position of the remaining amount indicator 12.

As shown in FIG. 2, the remote remaining amount detecting device 15
Is a sensor unit 17 attached to one of the viewing windows 14 via a dedicated clip 16, and a controller unit 18 for performing a predetermined signal processing on the remaining amount indicator position information and temperature information output from the sensor unit 17. A flexible cable 19 that connects the sensor unit 17 and the controller unit 18 and a bracket 20 that supports the controller unit 18.

The bracket 20 is provided with a hole (not shown) for allowing the protruding portion 7a (FIG. 1) of the plug member 7 to pass therethrough at the mounting portion of the on-site residual amount detecting device 5, and the protruding portion 7a.
After fitting the protective cover 13 to the
It is firmly attached to the plug member 7 together with the protective cover 13 via. In addition, in FIG. 2, the elements (cylindrical body 8, rod 9, operation tool 10, remaining amount display tool 1) located inside the protective cover 13 are shown.
2) and sensor section constituent elements described later are indicated by dotted lines.

FIG. 3 shows the structure of the sensor section 17. According to the present embodiment, the sensor unit 17 has a plurality of (for example, four) Hall elements 22 arranged in a line along the longitudinal direction of the sensor unit 17, and faces the observation window 14 (FIG. 2) to leave the remaining amount. Each Hall element 22 is installed so as to be located within the range of elevation of the display tool 12.

The Hall element 22 is characterized in that it outputs different voltages depending on the direction of the magnetic field passing through the element body.
The remote remaining amount detecting device 15 of the present embodiment utilizes the fact that the magnitude of the voltage output from each hall element 22 varies depending on the position of the remaining amount indicator 12 which is a paramagnetic material. The position of the remaining amount indicator 12 is calculated according to the output status.

The actual output of the Hall element 22 is
Even if they are placed in the same magnetic field, there are individual differences between the elements, and if they are left as they are, variations in the data will occur, and it is expected that the reliability of the calculated position of the remaining amount indicator is reduced. Therefore, in this embodiment, before the remote remaining amount detecting device 15 is attached to the on-site remaining amount detecting device 5, it is inspected in advance how much the output characteristic of each Hall element 22 deviates from the reference value. The respective shift amounts are stored in the nonvolatile memory (EEPROM) of the controller unit 18, respectively. Therefore, in actual measurement, the controller unit 1
8 corrects each signal from the sensor unit 17 by the above deviation amount,
The corrected display signal is used to calculate the actual display tool position.

In addition to the Hall element 22, the sensor section 17 has a thermistor 23 for detecting the temperature of the sensor section.
A heater 25 for heating the sensor unit body 24 is provided. On the other hand, the controller unit 18 has the current sensor unit temperature Ts detected by the thermistor 23.
In accordance with the above, the energization of the heater 25 is controlled, and the remaining amount indicator 12 is output by the output from the hall element 22 described above.
There is provided a control circuit (signal processing unit, heater control unit) 26 for calculating the position, in other words, calculating the remaining amount of fluid and outputting it to the outside.

FIG. 4 is a block diagram showing a schematic structure of the control circuit 26. The control circuit 26 is, as shown in the figure, an input port 26 for inputting a signal from the sensor unit 17.
a, a memory 26b including the above-mentioned EEPROM or RAM (random access memory), and a central processing unit (CPU) 26c for performing a predetermined calculation process on an input signal.
And an output port 26d for outputting a signal for driving the heater driving circuit 27 based on the calculated result, outputting the position information of the remaining amount indicator 12 to the outside, and a bus 26e for interconnecting these units. It is configured.

Further, the controller 18 further includes an A / D converter 28 for converting an analog signal (voltage) from each Hall element 22 or an analog signal from the thermistor 23 into a digital signal and guiding it to the input port 26a. 29 are provided.

Controller unit 1 configured as described above
The operation of No. 8 will be described. When the height position of the float 11 and the operating tool 10 changes with the change of the liquid level L (FIG. 1) of the liquefied gas F, the position of the remaining amount display tool 12 which is a paramagnetic material correspondingly changes up and down. Change direction. The change in the position of the remaining amount indicator 12 causes a change in the magnetic flux penetrating each Hall element 22 as it is, and the control circuit 26 causes each Hall element 2 to change.
The change of the analog signal output from 2 is digitized and input.

The input data is corrected by the CPU 26c for the above-mentioned variation in data between elements, and then subjected to a predetermined calculation to obtain the current position of the remaining amount indicator 12 (or the remaining amount of fluid). . Then, the remaining amount information thus obtained is output from the output port 26d in the form of a digital signal and is sent to the remote place R via a signal transmission means such as a telephone line T or radio. The remote location R may be a central control room for gas users or a sales office of a gas company.

On the other hand, the signal from the thermistor 23 input through the A / D converter 29 is processed by the CPU 26c to obtain the current sensor part temperature Ts, and the sensor part temperature Ts is the electronic part. It is determined whether the temperature is lower than a predetermined temperature Ta that guarantees the normal operation of. Here, if Ts <Ta, for example, the CPU
26c immediately calculates the difference ΔT, and stores it in advance in the memory 26b.
Using the temperature difference / heater energization time map stored in, the heater energization time corresponding to the difference ΔT is calculated (map search).

When the heater energization time is determined in this way, the CPU 26c then transmits the energization time information to the heater drive circuit 27 via the output port 26d, and the heater drive circuit 27 determines the determined energization time. Heater for time 25
To heat the sensor unit 17. With respect to this energization control method, the energization time may not be controlled by the temperature difference ΔT, and the sensor part temperature may always be detected and the sensor part temperature may be feedback-controlled.

As described above, according to this embodiment, the container 1
Even when the fluid filled inside is a low temperature liquefied gas and the sensor unit 17 is placed in an extremely low temperature environment, the control circuit 26 causes the heater 2 to operate based on the detected sensor unit temperature.
5 is energized to heat the sensor unit 17 to keep it at an appropriate temperature, so that the operation of electronic components (not shown) in the device and the Hall element 21 can be maintained in a normal state, and a remaining amount display tool to be detected. The reliability of the position can be increased.

As a method of detecting the position of the remaining amount indicator 12, there is a method of using a magnetoresistive element or a light emitting / receiving sensor in addition to the hall element 22. On the other hand, if there is the same magnetic force above and below that, there is a characteristic that the resistance value is the same, and there is the problem that it is difficult to distinguish between the upper and lower sides of one element. Further, in the case of the light emitting and receiving sensor, there is a problem that the sensor itself tends to be large in size, and even if it can be installed, it will also block other viewing windows 14, making it impossible to perform detection on site.

On the other hand, according to the detection method of this embodiment in which the hall elements 22 are arranged in a line in the vertical direction, the position of the remaining amount indicator 12 can be detected with high accuracy, and the sensor unit 17 itself is formed compactly. Can be used on-site residual quantity detection device 5
Even when it is attached to the camera, it does not block the viewing window 14 for site confirmation.

In the above-described embodiment, both the operating tool 10 and the remaining amount indicator 12 are made of magnets (paramagnetic material), but both are made of magnetic material, and at least one of them is paramagnetic. It may be configured by the body. Further, in the embodiment, the hall element 22 detects the height position of the remaining amount display tool 12, but the operation tool 10 may be a magnet and the position may be detected. Furthermore, in the present embodiment, a thermistor whose resistance changes with temperature is used as the means for detecting the temperature of the sensor portion, but another temperature sensor that is conventionally used may be used.

The fluid filled in the pressure vessel 1 is
For the accuracy of displaying the remaining amount, it is preferable to use a liquid that can increase the buoyancy of the float 11, but even in the case of compressed gas, the remaining amount can be displayed by adjusting the weight of the float 11.

[0034]

As described above, since the remote remaining amount detecting device according to the present invention has a function of controlling the temperature of the sensor part and maintaining the operation of the sensor part in a normal state, it is filled in the container. Accurate fuel volume data can be obtained even when the fluid is at a fairly low temperature.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a container equipped with a remaining amount detecting device and an on-site remaining amount detecting device according to the present invention.

2 is an external perspective view of the remaining amount detecting device and the on-site remaining amount detecting device shown in FIG. 1. FIG.

FIG. 3 is a schematic configuration diagram of a sensor unit that constitutes the remaining amount detection device of FIG.

FIG. 4 is a schematic configuration diagram of a controller unit that constitutes the remaining amount detection device of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Portable pressure container 2 ... Inner container 3 ... Outer container 5 ... Site residual quantity detection device 9 ... Rod 10 ... Operation tool 11 ... Float 12 ... Remaining quantity display tool 13 ... Protective cover 14 ... Peep window 15 ... Remote residual quantity Detecting device 17 ... Sensor part 18 ... Controller part 22 ... Hall element 23 ... Thermistor 25 ... Heater 26 ... Control circuit (signal processing part, heater control part) 27 ... Heater drive circuit F ... Fluid R ... Remote place T ... Telephone line

Claims (3)

[Claims] 1. A remote residual quantity which is mounted on a portable pressure vessel equipped with an on-site residual quantity detector and which converts the fluid residual quantity information in the container displayed on the on-site residual quantity detector into an electric signal for external output. A detection device, which is installed within a displacement range of the remaining amount indicator of the on-site remaining amount detector, detects a current position of the remaining amount indicator, and is connected to the sensor unit. A remote controller having a signal processing unit for converting the output signal of the above into an electric signal corresponding to the remaining amount of the fluid and externally outputting it, and a temperature control unit for controlling the temperature of the sensor unit and maintaining the sensor unit operation in a normal state. Remaining amount detection device. 2. The remaining amount indicator is made of a paramagnetic material that moves up and down inside the on-site remaining amount detector according to the liquid level in the container, and the sensor unit is arranged along the ascending / descending range of the magnetic material. 2. The remote remaining amount detecting device according to claim 1, wherein the remote remaining amount detecting device has a plurality of Hall elements. 3. The temperature control means detects a temperature of the sensor section, a heater arranged near the sensor section to heat the sensor section, and the temperature control section, according to the detected sensor section temperature. The remote remaining amount detecting device according to claim 1 or 2, further comprising a heater control unit that controls energization of the heater.