Tank liquid level measurement apparatus

Abstract

[Problem] To provide a tank liquid level measurement apparatus which, with a simple configuration, makes it possible to easily confirm the operation of a water-detecting float. [Solution] A tank liquid level measurement apparatus 1 comprising a stem 11 which is vertically disposed in an (underground) tank 2, an oil-detecting float 12 which is guided by the stem to follow the liquid level of fuel oil, a water-detecting float 13 which is disposed under the oil-detecting float and which is guided by the stem to follow the liquid level of water, and an operation-confirming member 14 which, between a lower face of the water-detecting float and the lower end of the stem, confirms the operation of the water-detecting float. The operation-confirming member can be provided with a bottom portion 14a which is located at the lower end of the stem, a holding portion 14b which is located on an upper face of the bottom portion so that the lower end of the stem is fit in the holding portion 14b, and an acting portion 14c which is rotatably supported by the bottom portion while abutting the lower face of the water-detecting float and which is biased by an elastic body (torsion spring) 14d toward the bottom portion.

Description

Tank liquid level measuring device

[0001] The present invention relates to an apparatus for measuring the liquid levels of fuel oil and water stored in tanks or the like buried underground.

[0002] The applicant has proposed a tank liquid level measuring device that can measure the fuel oil level in an underground tank buried underground and the amount of water accumulated at the bottom using a single liquid level detecting means (see Patent Document 1). In this device, water, which has a higher specific gravity than fuel oil, accumulates at the bottom of the underground tank, and a water detection float for detecting this water is located below an oil detection float for detecting fuel oil.

[0003] Japanese Patent Application Laid-Open No. 2001-4434

[0004] However, since the bottom of an underground tank is filled with not only fuel oil and water but also sludge, a type of sludge made up of rust and oil, if the water detection float becomes buried in the sludge, it will not function, making it impossible to determine the water level inside the underground tank. Furthermore, to check whether the water detection float is functioning properly, the liquid level detection means itself must be removed from the underground tank, a major undertaking. Furthermore, after removing the liquid level detection means, it was necessary to manually move the water detection float and check the change in the reading on the indicator.

[0005] The present invention has been made in consideration of the above problems, and has as its object to provide a tank liquid level measuring device that has a simple configuration and can easily check the operation of a water detection float.

[0006] In order to achieve the above-mentioned object, the present invention provides a tank liquid level measuring device comprising: a stem arranged vertically within a tank; an oil detection float guided by the stem to follow the fuel oil liquid level; a water detection float arranged below the oil detection float and guided by the stem to follow the water liquid level; and an operation confirmation member arranged between the underside of the water detection float and the lower end of the stem to confirm the operation of the water detection float.

[0007] According to the present invention, the operation of the water detection float (water level indication) can be easily confirmed by the operation confirmation member provided between the lower surface of the water detection float and the lower end of the stem.

[0008] In the tank liquid level measuring device, the operation confirmation member is configured to include a bottom portion located at the lower end of the stem, a holding portion located on the upper surface of the bottom portion and fitting into the lower end of the stem, and an operating portion that is rotatably supported on the bottom portion while abutting the underside of the water detection float and is urged toward the bottom portion by an elastic body, so that the operating portion can be held in a downward position (initial position) by the elastic body when not confirming operation.

[0009] Furthermore, by attaching a wire to the side of the end of the operating part for pulling the operating part upward, the water detection float can be pulled up from the bottom of the underground tank to check its operation.

[0010] Furthermore, by attaching the wire along a V-shaped groove formed on the side of the end of the operating part, the attachment position of the wire moves accordingly when the water detection float is pulled up, allowing the water detection float to be pulled up along the stem.

[0011] Furthermore, the lower end of the stem and the bottom of the operation confirmation member can be fixed at a position spaced apart from the center of the bottom, thereby preventing the stem from rotating and facilitating positioning of the stem.

[0012] Furthermore, by forming a convex portion on the surface of the bottom of the operation confirmation member that abuts against the operating portion, the bottom and the operating portion come into point contact, which effectively prevents sludge from getting caught.

[0013] Furthermore, by providing an inclined protrusion on the operating part that abuts against the underside of the water detection float, when the water detection float is pulled up by a wire, the water detection float can be lifted parallel to the stem in a nearly vertical position.

[0014] As described above, according to the present invention, the operation of the water detection float can be easily confirmed with a simple configuration.

[0015] Fig. 4 is a schematic diagram showing an installation procedure for a tank liquid level measuring device according to the present invention. Fig. 5 is a partially cutaway perspective view showing one embodiment of a tank liquid level measuring device according to the present invention. Fig. 6 is a partially cutaway front view of the tank liquid level measuring device of Fig. 2. Fig. 7 is a diagram showing an operation confirmation member provided in the tank liquid level measuring device of Fig. 2, where (a) is a perspective view and (b) is a plan view. Fig. 8 is an explanatory diagram of the operation of the operation confirmation member of Fig. 4. Fig. 9 is an enlarged view of the vicinity of the maintenance cap of Fig. 2.

[0016] Next, embodiments of the present invention will be described in detail with reference to the drawings.

[0017] FIG. 1 shows the installation procedure for the tank liquid level measuring device of the present invention. This tank liquid level measuring device 1 is placed vertically in an underground tank 2 installed at a gas station or the like, and an indoor display 3 is provided on the ground to display the measured values, etc., obtained by the tank liquid level measuring device 1.

[0018] As shown in Figures 2 and 3, the tank liquid level measuring device 1 comprises a stem 11 made of a metal tube, an oil detection float 12 that is slidably attached to the stem 11 and moves vertically in accordance with the fuel oil level, a water detection float 13 that is slidably attached to the stem 11 below the oil detection float 12 and moves vertically in accordance with the water level, an operation confirmation member 14 that confirms the operation of the water detection float 13, and a transceiver 20 arranged inside the riser pipe 10.

[0019] The stem 11 is made of a non-magnetic metal and has a pipe shape that is rigid enough to withstand magnetostriction and external forces.

[0020] The oil detection float 12 and the water detection float 13 are made of resin, stainless steel, or the like, and are configured as cylindrical bodies with an inner diameter slightly larger than the outer diameter of the stem 11 and an air chamber inside.

[0021] A transceiver 20 including a sensor unit and riser rings 16 and 17 are provided inside the riser pipe 10, and the riser rings 16 and 17 maintain the vertical position of the stem 11.

[0022] The maintenance cap 19 is integrated with the upper part of the riser pipe 10, and a level sensor cable (not shown) is inserted through the interior thereof, and the level sensor cable is led out to the indoor display 3 via a wiring box 21. An insertion hole 19a is drilled in the maintenance cap 19 to allow the wire 15 to pass through, and the upper end of the wire 15 can be hooked onto and locked onto a locking piece 21a of the wiring box 21.

[0023] An adjustment means 22 for adjusting the tension of the wire 15 is provided at the lower end of the transmitter / receiver 20. The entire tank liquid level measuring device 1 is fixed to the underground tank 2 by connecting the flange portion 18 to another flange portion (not shown) provided on the top surface of the underground tank 2.

[0024] The operation confirmation member 14 is provided between the lower surface of the water detection float 13 and the lower end of the stem 11 in order to confirm the operation of the water detection float 13 .

[0025] As shown in Figure 4, the operation confirmation member 14 comprises a bottom portion 14a located at the lower end of the stem 11 (Figures 2 and 3), a holding portion 14b located on the upper surface of the bottom portion 14a and fitting the lower end of the stem 11, and an operating portion 14c that is rotatably supported on the bottom portion 14a while abutting against the underside of the water detection float 13 and is urged toward the bottom portion 14a by a torsion spring (elastic body) 14d.

[0026] The wire 15 (FIGS. 2 and 3) for pulling up the actuating part 14c is attached by passing through a hole 14o formed in the side of the end of the actuating part 14c (the end at the upper left in FIG. 4(a) and the lower end in FIG. 4(b)). By forming a V-shaped groove 14h provided near the hole 14o, when the water detection float 13 is lifted by the wire 15, the actuating part 14c smoothly follows the movement of the wire 15, and by limiting the range of motion of the wire 15, it is possible to prevent the wire 15 from wrapping around the back surface of the actuating part 14c.

[0027] A hole 14g for fixing the bottom of the stem 11 is drilled in the bottom 14a of the operation confirmation member 14 at a position offset from the center. By forming the hole 14g at a position offset from the center, it is possible to prevent the stem 11 from rotating. Furthermore, when fitting the lower end of the stem 11 into the holding portion 14b, it is possible to position the stem 11, making assembly easier. This prevents assembly in the wrong direction and also prevents the wire 15 from being wrapped around the stem 11, making it impossible to pull the operating portion 14c.

[0028] A protrusion 14f is formed on the bottom 14a of the operation confirmation member 14. This allows the bottom 14a and the operating part 14c to come into point contact, preventing sludge from getting caught in the bottom 14a. This prevents the operating part 14c from sticking to the bottom 14a due to sludge, making it inoperable.

[0029] The actuator 14c has an inclined portion 14m, which is provided with a protrusion 14j. When one end of the actuator 14c is lifted by the wire 15, the angle of the actuator 14c relative to the horizontal increases, causing the protrusion 14j to abut against the lower end of the water float 13. The protrusion 14j is inclined so that it abuts perpendicularly against the lower end surface of the water float 13, regardless of the angle of the actuator 14c. As a result, when the water float 13 is pulled up by the wire 15, the force acting on the water float 13 from the protrusion 14j is primarily vertical, regardless of the position of the actuator 14c. Therefore, the water float 13 can be lifted nearly vertically (parallel to the stem 11), allowing the water float 13 to move smoothly without contacting the stem 11.

[0030] To prevent sludge from settling from the top of the underground tank 2, a protective member 14e is provided above the torsion spring 14d. This prevents the torsion spring 14d from becoming stuck with sludge and rendering the operating part 14c inoperable. Also, by providing a space 14k for discharging sludge and allowing the operating part 14c to move up and down, it is easy to remove sludge that has infiltrated the protrusion 14f with which it is in point contact. Furthermore, by forming a notch 14n in the operating part 14c, the range over which the operating part 14c can move without interfering with the stem 11 is widened.

[0031] Next, a procedure for checking the operation of the water detection float 13 using the tank liquid level measuring device 1 having the above configuration will be described with reference to FIG.

[0032] Figure 5 (a) shows the state before operation confirmation by the operation confirmation member 14. In this state, the operating part 14c is biased downward by the torsion spring 14d (Figure 4), and the bottom surface of the operating part 14c is at the same vertical level as the bottom surface of the bottom part 14a.

[0033] When the wire 15 is pulled up from the state shown in Fig. 5(a), the operating portion 14c of the operation confirmation member 14 rises as shown in Fig. 5(b), allowing the operation of the water detection float 13 to be confirmed. When the wire 15 is pulled up further, the operating portion 14c can be finally raised to the state shown in Fig. 5(c). As shown in Fig. 6, the wire 15 is led out from an insertion hole 19a formed in the maintenance cap 19, and the upper end portion 15a of the pulled-up wire 15 can be hooked and held by a locking piece 21a of the wiring box 21.

[0034] In this way, with the tank liquid level measuring device 1 installed in the underground tank 2, it is possible to check whether the water detection float 13 is operating correctly by operating the wire 15 on top of the tank liquid level measuring device 1 to move the operating part 14c. Furthermore, because the position of the water detection float 13 can be maintained, even if the indoor display 3 is installed in a location away from the underground tank 2, one person can check the position (change in numerical value) of the water detection float 13.

[0035] The illustrated embodiments are merely examples and are not intended to limit the technical scope of the present invention.

[0036] REFERENCE SIGNS LIST 1 Tank liquid level measuring device 2 Underground tank 3 Indoor indicator 10 Riser pipe 11 Stem 12 Oil detection float 13 Water detection float 14 Operation confirmation member 15 Wire 16, 17 Riser ring 18 Flange portion 19 Maintenance cap 20 Transmitter / receiver 21 Wiring box 22 Adjustment means

Claims

1. The tank comprises a stem positioned vertically within the tank, an oil detection float guided by the stem to follow the fuel oil level, a water detection float positioned below the oil detection float and guided by the stem to follow the water level, and an operation confirmation member between the lower surface of the water detection float and the lower end of the stem for confirming the operation of the water detection float. The operation confirmation member is, The bottom portion located at the lower end of the stem, A retaining portion located on the upper surface of the bottom portion and into which the lower end of the stem is fitted, A tank liquid level measuring device characterized by comprising an operating part that is rotatably supported at the bottom in contact with the lower surface of the water detection float and is biased toward the bottom by an elastic body.

2. (delete)

3. The tank liquid level measuring device according to claim 1, characterized in that a wire for pulling the operating part upward is attached to the side of the end of the operating part.

4. The tank liquid level measuring device according to claim 3, characterized in that the wire is attached along a V-shaped groove formed on the side surface of the end of the operating part.

5. (delete)

6. The tank liquid level measuring device according to claim 1, characterized in that a protrusion is formed on the surface of the bottom of the operation confirmation member that contacts the operation part.

7. The tank liquid level measuring device according to claim 1, characterized in that a projection that contacts the lower surface of the water detection float is provided at an angle on the operating part.