JP2008209217A - Electrostatic capacitance type liquid level gauge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure detection precision of a liquid level, and to facilitate flow-out of a liquid. <P>SOLUTION: A batch level gage 61 has an upper-end space regulating member 90, arranged concentrically with an inner cylinder 80 and an outer cylinder 82 functioned as cylindrical electrodes and engaged with the upper ends of the inner cylinder 80 and the outer cylinder 82, and a lower-end space regulating member 92 engaged with lower ends of the inner cylinder 80 and the outer cylinder 82. The lower-end space regulating member 92 has an upper end engaging part 92a, formed in an upper end to be engaged with the lower end of the inner cylinder 80, a lower-end engaging part 92c formed in a side lower than an upper step different part 92b to be engaged with the lower end of the outer cylinder 82; and a middle step different part 92e provided in an intermediate between the upper-end engaging part 92a and the lower-end engaging part 92c to form a cylindrical space 84. Since a through-hole 94 is discharged with oil liquid into a batch to make the oil liquid so as not to stay in a lower part of the cylindrical space 84 and will not affect the electrostatic capacitance generated between the inner cylinder 80 and the outer cylinder 82, since it is provided at a position lower than the lower end of the inner cylinder 80. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a capacitance type liquid level gauge, and more particularly to a capacitance type liquid level gauge configured to detect a capacitance according to a height position of a liquid level loaded in a hatch.

  For example, a tank truck is used as a means of delivering oil liquid loaded in each hatch at an oil tank station to a gas station, and the amount of oil liquid loaded or the remaining amount after unloading is stored in each hatch of the tank truck. A capacitance type liquid level gauge for measurement is provided (for example, see Patent Document 1).

  Oil tanks often load different types of oil into each hatch of a tank truck according to orders from multiple gas stations. Each tank is based on a hatch assignment slip assigned by a computer that stores reservation data. Loading into the hatch takes place. The driver of the tank truck confirms the hatch oil type and the loading amount so that contamination (mixing of different oil types) does not occur during loading and unloading.

  Therefore, the driver when unloading work confirms the hatch number, loading amount, and oil type described in the hatch allocation slip issued at the oil tank station, and further, the hatch loading amount is checked with the hatch liquid level gauge. After checking, start the unloading work. Then, after the unloading is completed, it is confirmed that the remaining amount of the hatch is reduced by unloading.

An electrostatic capacity level gauge used as a hatch level gauge for a tank truck has an inner cylinder and an outer cylinder that detect capacitance according to the height position of the liquid level and are arranged concentrically. And an upper end interval restricting member and a lower end interval restricting member that are fitted to the upper end and the lower end of the outer cylinder and restrict the radial positions of the inner cylinder and the outer cylinder.
JP 2000-309400 A

  The conventional capacitance level gauge is provided with a vent hole in the upper end distance regulating member, and a supply / discharge hole through which the oil liquid passes through the lower end distance regulating member, and the oil liquid is loaded into the hatch. The oil liquid also flows into the cylindrical space formed between the inner cylinder and the outer cylinder, and the oil liquid in the cylindrical space flows into the hatch with unloading. When oil liquid or moisture stays, the staying position may be detected as the liquid level (liquid level) even if the hatch liquid level falls below the level gauge. Moreover, there is a possibility that the measurement of the actual liquid level may be distorted due to a change in the capacitance value due to the retention (attachment) of moisture.

  In order to discharge the oil and water staying in this cylindrical space, it has been studied to provide a hole communicating with the cylindrical space at the lower end of the liquid level gauge. However, since the capacitance changes due to the presence of the hole, the non-measurement region where measurement cannot be performed at the portion where the hole opens is expanded.

  In addition, by reducing the hole diameter, the non-measurement area can be reduced. On the other hand, the oil liquid cannot be sufficiently discharged, and although the unloading is completed, the oil liquid and moisture remain in the cylindrical space. Therefore, there is a problem that the liquid level may be erroneously detected.

  In view of the above circumstances, an object of the present invention is to provide a capacitive liquid level gauge that solves the above-described problems.

  In order to solve the above problems, the present invention has the following means.

In the present invention, an inner cylinder and an outer cylinder for detecting capacitance according to the height position of the liquid level are arranged concentrically, and are fitted to the upper end and the lower end of the inner cylinder and the outer cylinder, respectively. In the capacitance type liquid level gauge having an upper end interval restricting member and a lower end interval restricting member for restricting a radial position so as to form a cylindrical space between the inner cylinder and the outer cylinder, the lower end interval restriction The member includes an upper fitting portion that is fitted to the lower end of the inner cylinder, and a lower fitting portion that is formed below the upper fitting portion so as to be fitted to the lower end of the outer cylinder. The above-described problem is solved by opening a hole that connects the cylindrical space and the inside of the hatch between the upper fitting portion and the lower fitting portion.
Moreover, this invention solves the said subject by the said hole being a through-hole provided so that it might penetrate from the lower end outer periphery of the said outer cylinder to a lower end inner periphery.
Further, according to the present invention, the hole is provided so as to penetrate the lower end interval regulating member, and communicates between the cylindrical space where one end of the hole opens and the inside of the hatch where the other end of the hole opens. The problem is solved by being a hole.

  According to the present invention, the lower end interval restricting member is provided with an upper fitting portion that is fitted to the lower end of the inner cylinder, and a lower fitting that is formed below the upper fitting portion so as to be fitted to the lower end of the outer cylinder. And a hole is formed between the upper fitting portion and the lower fitting portion so as to communicate the cylindrical space and the inside of the hatch. In addition to reducing the impact on the liquid level measurement due to fluctuations in the detection capacitance, when the liquid level inside the hatch drops due to unloading, the liquid in the cylindrical space is discharged from the hole and the liquid stays in the cylindrical space You can avoid it.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing an unloading system to which an embodiment of a capacitance type liquid level gauge according to the present invention is applied. As shown in FIG. 1, in the unloading system 10, when the tank truck 12 that delivers oil liquid arrives at the gas station, the oil type loaded in the hatch of the tank truck 12 and the underground underground in the gas station. An unloading operation is performed after confirming that the oil types in the tanks 21 to 23 match.

  For example, the oil types stored in the underground tanks 21 to 23 are different, and are determined in advance, such as regular gasoline in the underground tank 21, high-octane gasoline in the underground tank 22, and light oil in the underground tank 23.

  The tank truck 12 includes a tank 30 that is partitioned into a plurality of hatches 31 to 35. The plurality of hatches 31 to 35 are loaded with a plurality of types of oils according to the order of the delivery destination. For example, the first and second hatches 31 and 32 are gasoline, the third and fourth hatches. Each oil type is loaded in 33 and 34, such as light oil, and the No. 5 hatch 35 such as kerosene.

  Air-driven bottom opening / closing valves 41 to 45 that are opened when the oil liquid loaded in the hatches 31 to 35 is unloaded are provided at the bottoms of the hatches 31 to 35. The first and second bottom opening / closing valves 41 and 42 disposed on the front side (driver's seat side) of the bottom opening / closing valves 41 to 45 are connected in parallel to the first discharge port 51. The third to fifth bottom opening / closing valves 43 to 45 disposed on the rear side of the bottom opening / closing valves 41 to 45 are connected in parallel to the second discharge port 52.

  Further, a first electromagnetic valve 53 and a second electromagnetic valve 54 are disposed on the upstream side pipelines of the first discharge port 51 and the second discharge port 52, respectively.

  When the tank truck 12 arrives at the filling station, the driver (worker) sets the unloading hoses 55, 56 to the discharge ports 51, 52 communicated with the bottom opening / closing valves 41-45 provided at the bottoms of the hatches 31-35. One end is connected, and the other ends of the unloading hoses 55 and 56 are connected to the oil filling ports (injection ports) 24 to 26 of the underground tanks 21 to 23.

  The oil filling ports 24 to 26 are provided with oil type keys 28 to 30 for transmitting type data. The unloading hoses 55 and 56 are provided with oil type plugs (not shown) for reading the oil type data from the oil type keys 28 to 30.

  Further, the hatches 31 to 35 are respectively a capacitance level gauge for detecting the loading amount of the loaded oil liquid and the liquid level (liquid level) of the oil liquid after unloading. 61-65 are provided. The hatch liquid level gauges 61 to 65 measure the height position of the liquid level by the capacitance between the electrodes, and transmit the liquid level measurement signal to the unloading computer 40. The unloading computer 40 is mounted on the driver's seat of the tank lorry vehicle 12, the lower side of the tank lorry vehicle 12, or the like, and a driver or an operator who performs the unloading operation is displayed on a monitor (not shown) of the unloading computer 40. The liquid level height (liquid level) of each of the hatches 31 to 35 can be confirmed on the displayed screen.

  The underground tanks 21 to 23 are provided with SS liquid level gauges 71 to 73 for detecting the liquid level height (liquid level) of the stored oil liquid. The SS liquid level gauges 71 to 73 have transmitters 75 to 77 that wirelessly transmit detection signals corresponding to the liquid level height, and the detection signals transmitted wirelessly from the transmitters 75 to 77 are wirelessly received. Received by unit 78. The radio reception unit 78 is installed, for example, in the vicinity of the stop position of the tank truck 12 and is connected to the unloading computer 40 via a cable 79.

  The unloading computer 40 includes liquid level detection signals of the underground tanks 21 to 23 detected by the SS liquid level gauges 71 to 73, and liquid level detection signals of the hatches 31 to 35 detected by the hatch liquid level gauges 61 to 65. , And the movement of the oil liquid during unloading (the unloading situation from the hatches 31 to 35 to the underground tanks 21 to 23) is monitored.

  As unloading preparation work, a driver (or an operator) connects the other ends of the unloading hoses 55 and 56 to the oil filling ports 24 to 26, and oil seed plugs (not shown) of the unloading hoses 55 and 56 are oiled. When connected to the seed keys 28 to 30, the unloading computer 40 confirms the oil type of the oil liquid loaded in the hatches 31 to 35 for unloading and the oil types of the underground tanks 21 to 23 (both oil type information matches. Or not). And the unloading computer 40 is loaded in the hatch when the oil type information input from the wireless receiving unit 78 matches the oil type information of the underground tanks 21 to 23 connected to the unloading hoses 55 and 56. Allow unloading of fluids. Thereby, the bottom valve of the hatch to which the unloading permission signal is output among the bottom opening / closing valves 41 to 45 is opened, and the unloading of the hydraulic fluid of the hatch is started.

Thus, in the process of unloading, the hatch liquid level detection signals detected by the hatch liquid level gauges 61 to 65 are input to the unloading computer 40, and the unloading computer 40 is based on the hatch liquid level detection signals. The unloading state from the hatches 31 to 35 can be monitored.
Here, the structure of the hatch liquid level gauges 61 to 65 including the capacitance type liquid level gauge of the present invention will be described. In addition, since the hatch liquid level gauges 61 to 65 have the same configuration, the hatch liquid level gauge 61 will be described in detail below.

  FIG. 2 is a longitudinal sectional view of the hatch liquid level gauge 61. FIG. 3 is a longitudinal sectional view of the upper space regulating member of the hatch liquid level gauge 61. FIG. 4 is a longitudinal sectional view of the lower space regulating member of the hatch liquid level gauge 61. As shown in FIGS. 2 to 4, the hatch liquid level gauge 61 has an overall length corresponding to the depth of the hatches 31 to 35, and concentrically forms an inner cylinder 80 and an outer cylinder 82 that function as cylindrical electrodes. It is arranged in. The hatch liquid level gauge 61 is configured to detect a capacitance according to the height of the liquid flowing into the cylindrical space 84 formed between the inner cylinder 80 and the outer cylinder 82, A region where the inner cylinder 80 and the outer cylinder 82 face each other in the entire length of the cylindrical space 84 is a liquid level measurable range. Further, a cylindrical space 86 extending in the vertical direction passes through the inner cylinder 80 so that the oil in the hatch flows into the cylindrical space 86 from below.

  Further, the hatch liquid level gauge 61 has an upper end interval regulating member 90 fitted to the upper ends of the inner cylinder 80 and the outer cylinder 82, and a lower end interval regulating member 92 fitted to the lower ends of the inner cylinder 80 and the outer cylinder 82. .

  FIG. 5 is an enlarged vertical cross-sectional view showing a state in which the upper end interval regulating member 90 is attached. As shown in FIG. 5, the upper end interval regulating member 90 has a flange portion 90 a fitted to the inner periphery of the outer cylinder 82, and extends downward from the flange portion 90 a and has the same diameter as the outer diameter of the inner cylinder 80. A stepped portion 90b, a fitting portion 90c extending below the stepped portion 90b and having the same diameter as the inner cylinder 80, and a vent hole 90d penetrating the center in the vertical direction.

  The upper end of the inner cylinder 80 is constrained in a radial direction by being fitted to the fitting part 90c, and the upper end of the outer cylinder 82 is concentrically formed outside the inner cylinder 80 by being fitted to the flange part 90a. Thus, the position in the radial direction is regulated. Further, the upper portion of the cylindrical space 84 is formed by the flange portion 90 a and the step portion 90 b and is closed by the flange portion 90 a of the upper end interval regulating member 90. The upper end interval regulating member 90 has a configuration in which the flange portion 90a is fitted to the inner periphery of the outer cylinder 82, so that the extra length of the outer cylinder 82 can be absorbed.

In addition, a vent hole 82a is provided in the upper part of the outer cylinder 82 so as to penetrate the outer cylinder 82 in the radial direction and communicate the cylindrical space 84 with the tank. The vent hole 82a is for sucking or discharging air in accordance with the raising / lowering operation of the liquid level in the cylindrical space 84.
A plurality of vent holes 82a are provided at predetermined intervals in the circumferential direction at the same height position (a position below the flange 90a and a position above the lower stepped portion 90b). Therefore, since the vent hole 82a is provided at a position above the upper end of the inner cylinder 80, it does not affect the capacitance generated between the inner cylinder 80 and the outer cylinder 82, and the liquid level height detection accuracy. Is not reduced.

FIG. 6 is an enlarged vertical cross-sectional view showing a mounting state of the lower end interval regulating member 92. As shown in FIG. 6, the lower end space regulating member 92 includes an upper fitting portion 92 a that fits to the lower end of the inner cylinder 80, an upper step portion 92 b that contacts the lower end of the inner cylinder 80, and a lower end of the outer cylinder 82. A lower fitting portion 92c formed below the upper step portion 92b so as to be fitted to the lower fitting portion 92c, a lower step portion 92d provided below the lower fitting portion 92c and contacting the lower end of the outer cylinder 82, and an upper fitting It has a middle stepped portion 92e that is provided between the mating portion 92a and the lower fitting portion 92d and forms a cylindrical space 84, and a through hole 92f that penetrates the center in the vertical direction. Since the oil liquid in the hatch flows into the through hole 92f, a tapered surface 92g is provided at the upper end opening so that the oil liquid that flows into the cylindrical space 86 easily flows downward when unloading.
The middle stepped portion 92e closes the lower portion of the cylindrical space 84 below the upper stepped portion 92b, and opens to the lower outer periphery of the outer cylinder 82 at a position slightly above the middle stepped portion 92e. A communication hole 94 that communicates with the cylindrical space 84 is provided. A plurality of the communication holes 94 are provided at predetermined intervals in the circumferential direction at the same height position (a position below the upper step portion 92b and a position above the lower step portion 92d).
Since the communication hole 94 is provided at a position below the lower end of the inner cylinder 80, the capacitance generated between the inner cylinder 80 and the outer cylinder 82 is not affected, and the detection accuracy of the liquid level is lowered. I will not let you. Further, the communication hole 94 may have a smaller diameter than the height difference between the upper step portion 92b and the middle step portion 92e, and therefore, by providing a plurality of communication holes 94, oil is prevented from staying in the lower portion of the cylindrical space 84. Liquid can be drained into the hatch.

  FIG. 7 is a longitudinal sectional view showing a first modification of the lower end interval regulating member 92. In FIG. 7, the same parts as those in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted.

As shown in FIG. 7, the lower end space regulating member 92 </ b> A of Modification 1 is provided with a communication hole 96 that communicates the cylindrical space 84 with the through hole 92 f. The communication hole 96 is formed such that one end 96a opens at the lower end of the cylindrical space 84, the other end 96b opens into the through hole 92f, and the other end 96b is lower than the other end 96a. Inclined at an angle θ with respect to the direction.
Further, a plurality of communication holes 96 are provided in the circumferential direction, and in order to lower the liquid level during unloading, oil fluid that has flowed into the cylindrical space 84 together with the communication holes 94 is quickly transferred from the through hole 92f into the hatch. Can be discharged.
FIG. 8 is a longitudinal sectional view showing a second modification of the lower end interval regulating member 92. In FIG. 8, the same parts as those in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 8, the lower end interval regulating member 92 </ b> B of Modification 2 is provided with a plurality of communication holes 98 extending upward from the lower surface. Each of the communication holes 98 extends in the vertical direction, the upper end 98a extends to a position where it communicates with the lower part of the cylindrical space 84, and the lower end 98b opens on the lower surface of the lower end interval regulating member 92B.

  Therefore, each communication hole 98 can quickly discharge the oil liquid that has flowed into the cylindrical space 84 together with the communication hole 94 to reduce the liquid level during unloading.

  In the above-described embodiment, the case where the oil liquid is loaded on the hatches 31 to 35 of the tank truck 12 is described as an example. Of course, can be applied.

  In the said Example, although the liquid level meter which detects the liquid level of the hatch 31-35 of the tank lorry vehicle 12 was mentioned as an example, it was not restricted to this, Tanks other than a tank lorry vehicle (for example, structures, such as a building, Of course, the present invention can also be applied to a liquid level gauge for detecting the liquid level of a fixed tank fixed on the ground or an underground tank buried underground.

It is a block diagram which shows the unloading system to which one Example of the electrostatic capacitance type liquid level gauge by this invention was applied. It is a longitudinal cross-sectional view of the hatch liquid level gauge 61. It is a longitudinal cross-sectional view of the upper end space regulating member of the hatch liquid level gauge 61. It is a longitudinal cross-sectional view of the lower end space | interval regulation member of the hatch liquid level gauge 61. FIG. It is a longitudinal cross-sectional view which expands and shows the attachment state of the upper end space | interval regulation member 90. FIG. It is a longitudinal cross-sectional view which expands and shows the attachment state of the lower end space | interval regulation member 92. FIG. It is a longitudinal cross-sectional view which shows the modification 1 of the lower end space | interval control member. It is a longitudinal cross-sectional view which shows the modification 2 of the lower end space | interval control member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Unloading system 12 Tank truck 21-23 Underground tank 31-35 Hatch 40 Unloading computer 41-45 Bottom opening / closing valve 51,52 Discharge port 55,56 Unloading hose 61-65 Hatch liquid level gauge 80 Inner cylinder 82 Outer cylinder 84 Cylindrical space 86 Columnar space 90 Upper end spacing regulating member 92, 92A, 92B Lower end spacing regulating member 92a Upper fitting portion 92b Upper step portion 92c Lower fitting portion 92d Lower step portion 92e Middle step portion 92f Through holes 94, 96 , 98 communication hole

Claims (3)

An inner cylinder and an outer cylinder that detect capacitance according to the height position of the liquid level are arranged concentrically, and are fitted to the upper and lower ends of the inner cylinder and the outer cylinder, respectively, and the inner cylinder In the capacitive liquid level gauge having an upper end interval regulating member that regulates a radial position so as to form a cylindrical space between the outer cylinder and a lower end interval regulating member,
The lower end interval regulating member is
An upper fitting portion fitted to the lower end of the inner cylinder;
A lower fitting portion formed below the upper fitting portion so as to be fitted to the lower end of the outer cylinder,
A capacitance type liquid level gauge, wherein a hole communicating the cylindrical space and the inside of the hatch is opened between the upper fitting portion and the lower fitting portion.   The capacitance type liquid level gauge according to claim 1, wherein the hole is a through hole provided so as to penetrate from a lower end outer periphery of the outer cylinder to a lower end inner periphery.   The hole is a through hole that is provided through the lower end interval regulating member and communicates the cylindrical space where one end of the hole opens and the inside of the hatch where the other end of the hole opens. The capacitance type liquid level gauge according to claim 1.

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