JPH1183602A - Liquid level sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid level sensor which can be simply installed in various kinds of existing kerosine tanks and easily manufactured at a low cost. SOLUTION: A liquid sensor 10 detects the liquid level of a kerosine tank 1. An oil-resisting lead wire 13 is fixed to a float switch 12, which is suspended at a specified position for detecting the liquid level in the kerosine tank 1 by using a wire 14. The lead wire 13 is fixed along the wire 14. A chain type weight 25 which stretches the wire 14 in the vertical direction may be suspended below the float switch 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid level sensor, and more particularly, to a liquid level sensor installed in a kerosene tank of a heating device.

[0002]

2. Description of the Related Art In cold regions such as Tohoku and Hokkaido, a relatively large heating device using kerosene as a heat source such as central heating is often used. Usually, a kerosene tank having a capacity of about 100 to 200 liters is provided in each home to store kerosene. When the remaining amount of kerosene becomes low, contact the kerosene dealer and get refueled by a special delivery car.

In recent years, in order to increase the efficiency of kerosene replenishment work in such cold regions, kerosene tanks in each home are provided with a liquid level sensor for detecting the remaining amount of kerosene, and kerosene tanks are centrally managed at kerosene stores. A system to do this is being considered. In other words, the area and time when replenishment is needed are accurately grasped, and the replenishment work is made more efficient by patrolling each home at the optimal timing.

Conventionally, as a liquid level sensor attached to this type of kerosene tank, as shown in FIG.
1 and a float 102 are known. The float 102 is inserted into the shaft portion 101a of the resin case 101 so as to be vertically movable. The switch is turned on and off as the float 102 moves. The mounting plate 101b provided at the base of the shaft portion 101a is fixed to the inner wall of the kerosene tank 100 via packing or the like. Liquid level sensor lead wire 103
Is taken out of the kerosene tank 100 from the back side of the mounting board 101b so as not to come into contact with kerosene.

[0005]

However, when such a conventional liquid level sensor is attached to a kerosene tank,
Since the length of the shaft portion 101a of the float switch is constant, it may not be possible to install the float switch at the optimum liquid level detection position depending on the size or shape of the kerosene tank. For this reason, it is necessary to change the design of the liquid level sensor according to the type of kerosene tank, and it takes time to manufacture. Also, if there are various specifications of the liquid level sensor, depending on the kerosene tank,
The mounting operation may be complicated.

Accordingly, the present invention has been made in view of the above situation, and provides a liquid level sensor which can be easily installed in various existing kerosene tanks and which can be easily manufactured at low cost. It is intended to provide.

[0007]

A liquid level sensor for solving the above-mentioned problem is a liquid level sensor provided inside a kerosene tank, and a float switch capable of detecting a liquid level in the kerosene tank; Connected to the float switch,
An oil-resistant lead wire that transmits the liquid level detection signal to the outside of the kerosene tank, and a wire that suspends the float switch at a predetermined liquid level detection position is provided in the kerosene tank. Along with the lead wire. Further, in the liquid level sensor of the present invention, a chain-type or wire-type weight may be suspended below the float switch.

The wire is formed from a material such as stainless steel. Examples of the form of the wire include wires, chains,
It is good to use a wire, a bar, or the like. As a method of attaching the lead wire to the wire material, the lead wire may be spirally wound around the outer periphery of the wire material, or may be bundled at predetermined intervals with a band.

When the liquid level sensor of the present invention is mounted on a kerosene tank, for example, one end of the wire is fixed to the ceiling of the kerosene tank, and a float switch is fixed to the other end, and suspended at the liquid level detection position of the kerosene tank. Lower. The upper end of the lead wire
Take out from the tank ceiling. When the size and shape of the kerosene tank are different, the float switch can always be held at an optimum position by adjusting the length of the wire. Also, by attaching the lead wire along the wire, it is hard to hinder the attachment and detachment of the liquid level sensor.
It is stably held in the kerosene tank.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. A first embodiment of the present invention is shown in FIGS. As shown in FIG. 1, a kerosene tank 1 has a fuel supply port 2 and a sensor mounting port 3 formed in a ceiling portion. An oiling pipe 4 is provided on the bottom side surface, and a valve 5 is provided at the pipe outlet. A liquid level sensor 10 is attached to the sensor attachment port 3. As the sensor mounting port 3, a mounting port of a fuel gauge of the kerosene tank 1 is used. That is, a circular hole formed by removing the fuel gauge of the kerosene tank 1 is used with the liquid level sensor 10 as an attachment port.

The liquid level sensor 10 includes a float switch 12
Is connected to the lead wire 13. A float switch 12 is suspended from the bottom of the kerosene tank 1 by a wire 14. The lead wire 13 is spirally wound around the wire 14 and taken out from the upper portion of the tank. The wire 14 is a stainless steel wire. It has an outer diameter of about several mm and is formed linearly. The upper end of the wire 14
It is bent into a hook shape so as to be able to be locked on the upper part of the kerosene tank 1. The reason why the lead wire 13 is spirally wound around the wire 14 is to hold the lead wire 13 on the wire 14 without using a special fixing part or the like. Accordingly, the number of parts is small, and the manufacturing cost of the liquid level sensor 10 can be reduced. Further, by adjusting the number of turns of the lead wire 13, adjustment of the holding force and length of the lead wire 13 can be easily performed.

As a covering material of the lead wire 13, an oil-resistant insulating material is used. For example, ETFE (Copolymer of E
thylene and Tetrafluoro Ethylene), FEP (Polyfl
uoroEthylene Propylene, PFA (Perfluoroalkox)
y), PTFE (Polytetra Fluoroethylene), fluorine rubber, silicon rubber, or the like may be used. In particular, durability,
ETF with excellent chemical resistance, mechanical strength and radiation resistance
It is desirable to use E. Note that a conventional general lead wire is stored at a position where it does not come into contact with kerosene. Therefore, as a covering material, vinyl chloride or the like that takes only insulation into consideration is used. In the case of the present invention, as described above, by using a covering material made of an oil-resistant insulating material, it is possible to install the lead wire in a kerosene tank with the lead wire exposed.

[0013] As shown in FIG.
Comprises a resin case 21 and a float 22. A ring-shaped float 22 is inserted into the shaft portion 21a of the resin case 21 so as to be vertically movable. The lead wire 13 is taken out from the head part 21b. At a predetermined position of the shaft portion 21a, a stopper 21c for preventing the float 22 from falling off is provided. When the float 22 moves downward from the uppermost position, a magnetic force acts on a switch built in the shaft portion 21a, and a liquid level detection signal is output.

An L-shaped member 24 is used for attaching the wire 14 and the float switch 12. L-shaped member 24
Is formed by bending a plate such as stainless steel,
It has a vertical plate 24a and a horizontal plate 24b. The wire 14 is fixed to the vertical plate 24a at two places, upper and lower, and the horizontal mold 24b
, The head portion 21b of the resin case 21 is fixed.

A chain-type weight 25 is hung below the resin case 21. The uppermost ring 25a is passed through a pin hole 26 penetrating in the radial direction of the shaft portion 21a. Weight 2
The lower end of 5 reaches the bottom of the kerosene tank 1 and is bent. That is, the load of the weight 25 pulls the wire 14 in the vertical direction. Here, the reason why the chain type is used as the weight 25 is to apply an appropriate load to the wire 14 without being affected by the depth or shape of the kerosene tank. As the distance from the float switch 12 to the tank bottom increases, the load applied to the wire 14 increases. Thereby, even if the kerosene in the kerosene tank fluctuates, the wire 14 is less likely to roll.

As shown in FIG. 3, the float switch 12
The male screw member 27 and the female screw member 28 are used for attaching the lead wire 13 and the lead wire 13. The male screw member 27 is fixed in the resin case 21 via an O-ring 29 in the axial direction. The female screw member 28 is fixed to the outer periphery of the lead wire 13 with an adhesive. The lead wire 13 is passed through the male screw member 27 and the female screw member 28, and both are tightened via the O-ring 30. A sealing material 31 is embedded in the gap between the resin cases 21. Thereby, intrusion of kerosene into the resin case 21 is reliably prevented.

As shown in FIGS. 4 and 5, a mounting member 40 for mounting a liquid level sensor to the kerosene tank 1 includes an upper plate 41,
A lower plate 42, a bolt 43 and a guide wire 44 are provided. A tap hole 45 is formed in the center of the upper plate 41 and the lower plate 42, and the bolt 43 is fitted into the tap hole 45. The wire 14 is fixed to the lower plate 42 with a screw so that the length can be adjusted. The lead wire 13 and the guide wire 44 pass through the shaft hole of the bolt 43. The upper plate 41 and the lower plate 42 are arranged with the ceiling plate of the kerosene tank 1 interposed therebetween, and the tapped holes 4 are formed.
Tighten the bolt 43 to 5. Then, the liquid level sensor 10 is fixed at a fixed position on the ceiling plate. The guide wire 4
4 prevents the lower plate 42 from falling into the kerosene tank. The guide holes 46 provided adjacent to the tapped holes 45 of the upper plate 41 and the lower plate 42 are used for mounting the upper plate 41.
And the lower plate 42 can be positioned.

When the liquid level sensor 10 is mounted on the kerosene tank 1, first, the distance from the gauge mounting port 3 to the liquid level detecting position is measured. Since the depth to the liquid level detection position varies depending on the type of kerosene tank, the distance may be measured by actually inserting the wire 14 into the kerosene tank 1. Then, FIG.
As shown in (B), if necessary, the length of the wire 14 is adjusted so that the float switch 12 is at the liquid level detection position, the upper bent portion is opened, and the wire is sandwiched in the guide hole 46 by elastic force. Thereafter, the upper plate 42 and the lower plate 43 are interposed between the ceiling of the kerosene tank 1 and tightened with bolts 43. Since the liquid level sensor 10 is mounted on the ceiling of the kerosene tank 1, even if kerosene remains in the tank, since the liquid level sensor 10 is mounted on the tank ceiling, it can be implemented without removing kerosene. . Therefore, the working time can be significantly reduced.

When the kerosene tank 1 contains a sufficient amount of kerosene, the liquid level of the kerosene is higher than the liquid level detection position, so that the float 22 floats up and is held at the uppermost position.
The float switch is kept on. At this time, no electric signal is output to the computer of the kerosene store. On the other hand, when the amount of kerosene decreases and the liquid level of the kerosene reaches the liquid level detection position, the float 22 moves downward together with the liquid level, and the float switch 12 is turned off. Then, a liquid level detection signal is output to the computer of the store through the lead wire 13 to notify the kerosene supply time.

Next, a second embodiment of the present invention will be described with reference to FIGS.
Shown in In the second embodiment, a float switch 50 is provided with two floats 52 and 53. Resin case 5
1 is formed with a shaft portion 51a that is sufficiently longer than the thickness of the floats 52 and 53. Stoppers 51c and 51d are formed at positions that partition the shaft portion 51a at equal intervals. The floats 52 and 53 are inserted into the upper and lower stages of the shaft 51a so as to be vertically movable. A switch that is activated by the movement of each of the floats 52 and 53 is provided inside the shaft portion 51a.

According to the second embodiment, the floats 52 and 53
The liquid level of the kerosene tank 1 is detected at two locations. That is,
When one of the floats 52 and 53 detects the liquid level, it outputs a detection signal to the outside. Therefore, the accuracy of the liquid level detection is improved, and the reliability of the liquid level sensor can be improved.

The operation of the float switch 50 may be such that the liquid level is detected in two stages by the floats 52 and 53. In this case, first, the float 52
Transmits a first detection signal to the administrator when the liquid level is detected to notify that the time for replenishing kerosene is approaching.
Next, when the float 53 detects the liquid level, a second detection signal is transmitted to the administrator to notify that the liquid level has reached the kerosene supply position. If the liquid level in the kerosene tank is detected stepwise as described above, the reliability of the kerosene liquid level detection can be improved. In particular, in tanks with low consumption, even if consumption stops immediately before the liquid level detection position due to bad timing, the liquid level is detected at two locations, floats 52 and 53, so that the kerosene replenishment time can be accurately notified. become.

In the second embodiment, a wire-type weight 55 is mounted below the float switch 50. FIG.
As shown in (1), the tip of the weight 55 passes through the through hole of the shaft 51a and is stopped by the ring 56. The lower end of the weight 55 is set to a length that reaches the bottom of the kerosene tank. According to the weight 55, the length can be easily adjusted as compared with the chain type weight, and the depth can be set before mounting. The other configurations and effects of the second embodiment are the same as those of the first embodiment.

[0024]

As described above, the liquid level sensor of the present invention has the following excellent effects. (a) The float switch can be easily installed at the optimum liquid level detection position according to the size and shape of the kerosene tank without removing kerosene. (b) There is no need to change the specifications of the float switch depending on the type of kerosene tank, and it can be manufactured at low cost. (c) Uses oil-resistant lead wires, so it has excellent durability. (d) Even if the kerosene tank is tilted, the reliability of the kerosene liquid level detection is high because the wire keeps verticality.

[Brief description of the drawings]

FIG. 1 is an overall view showing a liquid level sensor according to a first embodiment of the present invention.

FIG. 2 is a side view of the liquid level sensor according to the first embodiment of the present invention.

FIG. 3 is a partially enlarged sectional view showing a float switch of the liquid level sensor according to the first embodiment of the present invention.

FIG. 4 is an exploded perspective view showing an attachment of the liquid level sensor according to the first embodiment of the present invention.

FIGS. 5A and 5B show a mounting device for the liquid level sensor according to the first embodiment of the present invention, wherein FIG. 5A is a plan view and FIG.

FIG. 6 is a side view of a liquid level sensor according to a second embodiment of the present invention.

FIG. 7 is a partial perspective view showing a float switch of a liquid level sensor according to a second embodiment of the present invention.

8A and 8B show a liquid level sensor according to a conventional example, and FIG.
Is a perspective view, and (B) is a side view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Kerosene tank 2 Filling port 3 Sensor mounting port 4 Lubrication pipe 5 Valve 10 Liquid level sensor 12 Float switch 13 Lead wire 14 Wire (wire material) 21 Resin case 22 Float 24 L-shaped member 25 Weight 40 Fixture 41 Upper plate 42 Lower plate 43 bolt 44 guide wire

Claims (2)

[Claims] 1. A liquid level sensor provided inside a kerosene tank, comprising: a float switch capable of detecting a liquid level in the kerosene tank; and a float switch connected to the float switch and receiving the liquid level detection signal from the kerosene tank. And an oil-resistant lead wire for transmitting the float switch to a predetermined liquid level detection position in the kerosene tank, and attaching the lead wire along the wire. Characteristic liquid level sensor. 2. The liquid level sensor according to claim 1, wherein a chain-type or wire-type weight is hung below the float switch.