JPS581728B2 - Liquid level indicator - Google Patents

Description

[Detailed description of the invention] The present invention relates to a liquid level gauge.

A float suspended by a cable is floated on the liquid level whose displacement or fluctuation is to be detected, and the displacement of the float that follows the displacement or fluctuation of the liquid level (hereinafter simply referred to as displacement) is measured by the -
A liquid level gauge is known in which the rotation of a rotating shaft around which the end is wound is detected and transmitted to a pointer via a gear coupling mechanism to display displacement of the liquid level.

In liquid level gauges with such a configuration, attempts have been made to amplify the rotation of the rotating shaft using a gear mechanism in order to detect minute displacements in the liquid level, but due to backlash and other play in the gears, the liquid level It is difficult to increase sensitivity to changes beyond a certain level.

For example, it is undesirable for safety and pollution to leak oil from underground oil storage tanks at gasoline filling stations.

Since such oil leaks are practically undetectable when oil sales are frequent, it is important to check the level of oil in the tank after a certain period of time after sales have been stopped at night or before a holiday. It is common to detect by displacement.

However, since such oil leakage is usually relatively small and the displacement of the liquid level is small in a large oil storage tank, it cannot be detected by the conventional liquid level gauge having the above-mentioned configuration.

In addition, in cases such as those described above, recording the oil level in the tank at the end of business hours the previous day or night before and comparing it with the level just before business hours begin the next morning may lead to errors in reading the guideline or recording. There is.

Therefore, it is desired to develop a liquid level meter that has sufficient sensitivity to even minute fluctuations in the liquid level and can accurately record and display displacements in the liquid level.

The present invention provides a liquid level gauge that meets these demands.The first invention uses a float that follows the surface of the liquid contained in a container to detect changes in the liquid level using a cable, reel, or deceleration mechanism. In the device that displays the amount or liquid level of the liquid by transmitting the information to the display mechanism via a reel, etc., if a rotating member having a circular solid surface is directly fixed to the axis of the reel and can rotate together with this rotating axis. The present invention is characterized in that the change in the liquid level is converted into a rotational displacement of the circumferential surface of the rotating member and displayed in an enlarged manner to detect minute changes in the liquid level.

The second invention uses a float that follows the surface of the liquid contained in a container to transmit changes in the liquid level to a display mechanism via a cable, reel, deceleration mechanism, etc., and displays the amount or level of the liquid. In the apparatus, a first rotating member having a circumferential surface is directly fixed to the shaft of the reel so as to be rotatable together with the rotating shaft, and changes in the liquid level are detected based on the circumference of the rotating member. The rotational displacement of the surface is converted into an enlarged display, and a second rotating member of the same type as the first rotating member is used.
rotatable members are rotatable independently from the first rotary member on the same axis as the rotary shaft and arranged in parallel in close proximity to the first rotary member, It is characterized in that minute changes in the liquid level are detected by rotational displacement of the circumferential surface of the second rotating member relative to the circumferential surface.

The illustrated embodiment will be described in detail below.

In FIG. 1, 1 is a fuel storage tank buried underground at a site such as a gas station, 2 is a fuel meter, 3 is a liquid level gauge of the present invention, and 4
4 is a cable, and 4 is a float suspended from the cable 4, which floats on the oil surface in the tank and moves up and down following the displacement of the oil surface.

2 to 5 show details of a liquid level gauge according to an embodiment of the present invention.

Reference numeral 5 denotes a casing whose upper surface is open, and 6 a transparent plate whose upper surface opening of the casing 5 is sealed by a metal ring 8 and screws 9 via an O-ring 7.

A scale plate 10 is installed below the transparent plate 6 with a gap G in between, and has a scale 11 for indicating the amount of oil in the tank and a window 12.

A drum scale appears in the window 12 to indicate minute liquid level displacements, which will be described later.

Reference numeral 13 denotes a frame fixed within the casing 5 by screws 14, to which the internal mechanism of the liquid level gauge is mounted and supported.

The display board 10 is also fixed to the frame 13 with screws 15 (FIG. 5).

The cable 4 for suspending the aforementioned float 4' passes through a through hole 16 in the bottom wall of the casing and is wound around a reel 17.

The reel 17 is fixed to a rotating shaft 18, and this rotating shaft 18 is supported by the frame 13.

Another reel 19 is fixed to the rotating shaft 18 and a constant force spring 2
0(7) - half wound.

The other half of the constant force spring is wound around a reel 21 supported on the frame 13.

As is well known, a constant force spring is used to maintain the constant force of the reel 19 and the reel 1γ and the rotating shaft 18 no matter what rotational position the reel 19 is in.
A constant rotational force (counterclockwise rotational force in Fig. 5) is applied to the float, and this rotational force is balanced by the difference between the weight of the float and the buoyant force.

Therefore, the float 4 does not fluctuate relative to the liquid level (sinking or rising with respect to the liquid level) at different positions above and below the liquid level, and can accurately follow the displacement of the liquid level. Displace.

The rotation of the reel 1γ and therefore the rotating shaft 18 due to the displacement of the oil level in the tank 1 is caused by a gear 22 fixed to this rotating shaft 18.
, a gear 23 meshing with this gear, a gear 25 fixed to a rotating shaft 24 to which this gear is fixed, a gear 26 meshing with this gear 25, a rotating shaft 27 to which this gear 26 is fixed.
A pointer 31 is decelerated via a bevel gear 28 fixed to the bevel gear 28, a bevel gear 29 meshed with the bevel gear 28, and a pointer 31 fixed to the upper end of the vertical shaft 30 to which the bevel gear 29 is fixed (FIG. 5).
is transmitted to.

Therefore, the pointer 31 rotates in accordance with the liquid level to indicate the scale 11 on the display board 10.

Scale 11 is 1 when the full scale is 10 kiloliters, for example.
Since the scale is 100 liters and the rotation of the rotating shaft 18 is considerably slowed down, the pointer 31 cannot be sensitive to the displacement of the liquid level of 1 to several liters as described above, and therefore, the pointer 31 cannot be sensitive to such minute displacements. cannot be displayed.

Therefore, it is conceivable to amplify the rotation of the rotary shaft 18 with gears as described above, but this structure also cannot obtain sufficiently high sensitivity due to patch crashes and the like as described above.

In the present invention, in consideration of this point, the display drum or disk (first rotating member having a circumferential surface) 32 is directly fixed to the rotating shaft 18, and a scale 33 is attached to the circumferential surface of this drum. The scale is made to appear in the window 12 of the display board 10, and by attaching the drum 32 directly to the rotating shaft 18, it can be sensitive to minute rotations of the rotating shaft 18 based on minute displacements of the liquid level. At the same time, by selecting the diameter of the drum 32 to be larger than the diameter of the reel 1T, the displacement of the liquid level (float 5 and therefore the cable 4) is amplified or expanded to the rotational displacement of the circumferential surface of the drum 32. It can be expressed as

This increase rate or expansion rate is determined by the diameter of the reel 17 and the drum 32.
It is determined by the ratio of the diameters of , and can be set to a desired value by appropriately selecting these diameters.

34 is a separate rotating shaft disposed on the same axis as the rotating shaft 18, and is connected to the pairing push 3 on the peripheral wall of the casing 5.
4' is rotatably supported.

A second (reference) drum or disc (a second rotating member having a circumferential surface) 35 similar to the drum or disc 32 is fixed to the inner end of the rotating shaft 34, and an operating knob is fixed to the outer end. 36
is fixed.

The same scale 36 as the first drum 32 is attached to the circumferential surface of the second drum 35, and both drums 32 and 35 are arranged side by side with a slight gap between them, and a part of each scale is as described above. It is designed to appear within the window 12 of the display board 10.

37 is a wiper for removing fog from the inner surface of the transparent plate 6;
It is supported by a shaft 38.

Reference numeral 39 denotes a mounting plate which is attached to a clamping plate 40 and screws 41 so as to close the central hole 6'' (FIGS. 4 and 5) of the transparent plate 6.

A rotating shaft 38 of the wiper 37 is supported by a mounting plate 39, and an operating knob 42 is fixed to the outer end of the rotating shaft 38, and the wiper is moved by turning this knob.

43 (FIG. 1) is a pipe communicating the level gauge and the oil storage tank, 44 (FIG. 5) is a connecting pipe, and the cable 4 extends downwardly through this pipe 43.

A pipe 45 vertically passes through the casing 5 of the level gauge, and its upper end is connected to a through hole 46 (FIG. 5) in the mounting plate 39, and its lower end is opened and communicated with the connecting pipe 44.

This pipe 45 is used to measure the liquid level and inspect impurities (for example, water) by inserting a rod into the oil storage tank 1 as necessary.

The through hole 46 is normally closed with a cap 47.

In the above configuration, the amount of liquid in tank 1 (height of the liquid level)
The pointer 31 indicates the scale 11 and the window 12
A portion of the scale of the drum 32 appears within (FIG. 2).

For example, at a gas station, the scale on the other drum 35 is aligned with the scale on the drum 32 that appears in the window 12 by operating the knob 36.

When a slight displacement of the liquid level occurs, the drum 32 moves to the drum 35.
Since the scale of the former is displaced from the scale of the latter (Figure 6), for example, before business starts the next morning, it is possible to determine whether or not there is a displacement of the liquid level in the tank (increase or decrease in liquid) due to such a deviation in the scale. and its amount can be easily known.

The graduations of the drums 32 and 35 may be expressed in units that express capacity (for example, deciliters, liters, etc.), or the units that express length may be expressed as units of liquid level (millimeter, liter, etc.).
centimeters, etc.) may be used.

Incidentally, instead of using the second drum 35, it is also possible to provide an index 48 in the window 12 as shown in FIG. 7, and to know the rotational displacement of the drum 32 (displacement of the liquid level) with respect to the index 48.

Of course, in this case, the value displayed on the drum 32 at a certain point in time (for example, when a gas station closes) is stored or recorded.
It is necessary to compare the displayed value after a certain period of time.

Although the illustrated embodiment has been described above, the present invention is not limited to this, and various modified embodiments are possible.

For example, various arrangement configurations of the gear reduction mechanism may be considered other than the illustrated example.

For example, it is possible to reduce the speed not only with spur gears as shown in FIGS. 3 to 5, but also with other types of gears.

Further, the display mechanism is not limited to the display using a pointer, but may also be a digital display system using, for example, an inverted display board, and the rotation of the rotating shaft can also be detected electrically or by other methods to provide remote instructions.

Further, the display and reference drums are not necessarily limited to drums, and may be disks, in short, any rotating member having a circumferential surface may be used.

As described above, according to the present invention, since the display drum (or disk) is directly attached to the shaft that rotates or rotates in accordance with the displacement of the liquid level, there is no error caused by backlash, which occurs when gears are used, and the liquid It is possible to faithfully and accurately respond to minute displacements of the surface, and by appropriately selecting the diameter of the display drum, minute fluctuations in the liquid level can be freely amplified or magnified.

Furthermore, a reference drum is provided adjacent to the display drum, and the displacement of the liquid level can be determined by the deviation of the corresponding scale of the display drum that matches the scale of this reference drum, making it possible to easily and accurately measure the displacement of the liquid level and its amount. You can know.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view showing the schematic configuration of a filling station in which a level gauge of the present invention is installed, Fig. 2 is a plan view of a liquid level gauge according to an embodiment of the present invention, and Fig. 3 is a view from above from the display board. Figure 4 is a cross-sectional view of the IV-TV line in Figure 2 with parts removed, Figure 5 is a diagram of the IV-TV line in Figure 2.
6 is a diagram showing a state in which the display drum of FIG. 2 is rotationally displaced with respect to the reference drum, and FIG. 7 is a view showing the vicinity of the window of the display board of another embodiment. FIG. 3...Liquid level gauge, 4...Cable, 4'
...Float, 10...Scale plate, 12
...Window, 13...Frame, 1γ...
... Reel, 18, 24. 27 ... Rotating shaft, 20 ... Constant force spring, 22, 23, 25, 2
6, 28, 29...gear, 32...
...Display drum, 35...Reference drum, 37
...Wiper, 43...Pipe.

Claims (1)

[Claims] 1. Using a float that follows the surface of the liquid contained in a container, changes in the liquid level are transmitted to a display mechanism via a cable, reel, deceleration mechanism, etc., and the amount or level of the liquid is displayed. In the apparatus, a rotating member having a circumferential surface is directly fixed to the shaft of the reel so as to be rotatable together with the rotating shaft, and changes in the liquid level are detected on the circumferential surface of the rotating member. A liquid level gauge characterized in that minute changes in the liquid level are detected by converting the rotational displacement into an enlarged display. 2 Using a float that follows the surface of the liquid contained in a container, changes in the liquid level are transmitted to a display mechanism via a cable, reel, deceleration mechanism, etc., and the amount or level of the liquid is displayed. In the apparatus, a first rotating member having a circumferential surface is directly fixed to the shaft of the reel so as to be rotatable together with the rotating shaft, and a change in the liquid level is caused by a rotational displacement of the circumferential surface of the rotating member. a second rotating member of the same type as the first rotating member can be rotated independently from the first rotating member on the same axis as the rotating shaft, and , are arranged in parallel and close to the first rotating member, and cause minute changes in the liquid level by relative rotational displacement of the circumferential surface of the first rotating member with respect to the circumferential surface of the second rotating member. A liquid level gauge characterized by detecting.