JPH01281323A - Volume sensing device for liquid tank - Google Patents

Abstract

PURPOSE:To improve the sensing accuracy with a simplified structure of the captioned device for an airtight tank used for a liquid fuel burning apparatus by pivotably supporting one end of the tank supporting tray in a horizontal position with the other end supported by a spring, and sensing the change of spring flexing. CONSTITUTION:One end of a stay 10 for a tray 6 is pivotably supported by a support pin 24 disposed in the bottom plate 14 in a horizontal position with the other end supported by a coil spring 21, and the flexing displacement of the spring is detected by a load sensor 25. In this constitution, the total weight of the tank 1 is supported by a pin 8, and the load is concentrated near the pin 8. Where the distances between the pin 8 and support point 24 and between the pin 8 and weight sensor 25 are respectively designated as (a) and (b), the load of (gross weight of liquid fuel in the tank 1)X(b)/(a+b) is applied to the load sensor 25. By detecting the change of loading by means of the spring displacement of the weight sensor 25, the fuel volume can be measured. This way, the accuracy can be improved with a simplified structure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a detection means for detecting the content of an airtight tank used, for example, in a liquid fuel combustion device.

[Prior Art] An example of a conventional tank capacity detection device is shown in FIGS. 6 and 7. An airtight tank 1 containing liquid fuel has a cap 2 only at the bottom. There is a shutoff valve 3. This shutoff valve 3 is urged in a closing direction, that is, downward, by a coil spring 5 provided on a valve seat 4. The valve seat 4 has a generally cylindrical shape and is provided with a slit (not shown) through which liquid fuel can pass.

The airtight tank 1 is supported by a saucer 6. This support is performed by a receiver 7 provided at the center of the receiver 6. Further, in a state where the airtight tank 1 is supported, the edge of the saucer 6 is located at a higher position than the lower edge of the base 2. This prevents the liquid fuel from overflowing into the tray 6. A pin 8 is provided in the center of the receiver 7 of the tray 6 in an upward direction. This pin 8 functions to push up the shutoff valve 3 and open it. A transport pipe 9 is connected to the bottom of the saucer 6 to send the liquid fuel in the saucer 6 to the outside. The saucer 6 is fixed to a fixed leg 10, and this fixed leg 1o is further fixed to a holding plate 11. One end of this holding plate 11 is
It is welded to one end of the flexible plate 12 located on the lower side. Further, the other end of the flexible plate 12 is welded to the flange portion of the support Fi, 13 located below it. Support plate 13
is welded to the lower bottom plate 14. Above holding plate 1
1. The flexible plate 12 and the support plate 13 collectively form an approximately 2-shaped cross section. This Z-shape is bent by the weight of the airtight tank, and the central flexible plate 12 may be distorted. This deflection plate 12 is provided with a strain gauge 15 for detecting its distortion, and this strain gauge 15 is further connected to an amplifier 16 and then to a display device (not shown).

The operation of this conventional example will be explained below. When the tank 1 is placed and supported on the saucer 6, the bottle 8 pushes up the shutoff valve 3 to open it, and liquid fuel flows out into the saucer 6. When the liquid level of the liquid fuel reaches the height of the lower edge of the nozzle 2, the flow of air into the tank 1 stops, and therefore the outflow of the liquid fuel stops. Thereafter, the liquid fuel in the saucer 6 is sent to an external device, for example, a combustion device, via a transport pipe 9. Since the liquid level drops by the amount that is sent, liquid fuel is replenished from the tank 1 into the saucer 6 by that amount.

Depending on the change in the total weight of the liquid fuel remaining in the tank 1 and the saucer 6, the amount of deflection of the flexible plate 12 changes, and the distortion changes. This change in strain is converted by the strain gauge 15 into a change in electrical resistance value. Although this change in resistance value is a minute change, it can be amplified by the amplifier 16 and displayed on a display device (not shown). This allows you to know the amount of remaining liquid fuel.

[Problems to be Solved by the Invention] As described above, in the conventional device, the strain gauge 15 is bonded to the deflection plate 12, and the amplifier 1 is used to amplify the strain change.
I used 6 and had to get 7.

This has the disadvantage that the device becomes expensive.

SUMMARY OF THE INVENTION An object of the present invention is to obtain a capacitance detection device that is inexpensive and can sufficiently satisfy the required detection accuracy.

[Means for Solving the Problems] The present invention includes a fulcrum that horizontally supports one end of a saucer that supports a tank, a spring that supports the other end of the saucer, and a sensor that detects changes due to stagnation of this spring. It is characterized by having the following.

[Function] Conventionally, the tank capacity was detected based on the distortion of the deflection plate.The reason for this is that this capacity detection device reduces the rise and fall of the liquid level to prevent negative effects on, for example, combustion equipment. It's for a reason.

In contrast, in this invention, in order to reduce the vertical movement of the liquid level, the vertical displacement near the center of the saucer can be made sufficiently small, and the deflection of the spring supporting the other end can be sufficiently expanded. .

Therefore, the accuracy can be sufficiently increased without using a conventional amplifier or the like.

[Example] An example of the present invention will be described below with reference to FIGS. 1 to 5.

As shown in FIG. 2, the shutoff valve 3 has a long stopper portion 22 that is shaped to wrap around a coil spring 21 and comes into contact with the upper bottom portion of the valve seat 4.

Due to this abutment, the tank 1 has a structure that does not fall below a certain position. A gasket 23 is provided in the gap between the tank 1 and the saucer 6 that is created for this reason. Also, due to the abutment, most of the weight of the tank 1 is supported by the bottle 8. Although the tank 1 is not shown, it is supported by a guide plate to provide a minimum supporting force to the extent that it does not fall over.

As shown in FIG. 1, one end of the fixing plate 1s10 of the saucer 6 is horizontally supported by a fulcrum pin 24 provided on the bottom plate 14. As shown in FIG. A spring that supports the other end of the saucer 6 and a sensor that detects displacement due to the deflection of this spring are built into the weight sensor 25 .

This weight sensor 25 is attached to a pedestal 26 provided on the bottom plate 14, and supports the other end of the pedestal.

Next, details of the weight sensor 25 will be explained with reference to FIG. An upper base 31 is fitted into a lower base 32 so as to be movable up and down, and a spring 33 is provided between the upper base 31 and the lower base 32. A carbon resistance surface 34 is provided on the inner bottom surface of the lower base 32. A short circuit plate 3 is provided between this carbon resistance surface 34 and the upper base 31.
5 is installed. This shorting plate 35 is approximately W-shaped and has a gentle curve. Further, electric wires 36 and 37 are connected to both ends of the carbon resistance surface 34, and this weight sensor 25
guided externally.

The operation of this embodiment will be explained below. First, the third
The function of the weight sensor 25 shown in the figure will be explained based on FIGS. 4 and 5. Spring 3 does not apply the load of tank 1, etc.
3 is extended, the W-shaped shorting plate 35 is in contact with the carbon resistance surface 34 at two narrowly spaced points as shown in FIG. At this time, when a voltage is applied to the electric wires 36 and 37, a current flows as indicated by the broken line arrow in the figure.

When the load of tank 1 etc. is applied and the spring 33 contracts, W
The shorting plate 35 of the mold is compressed and deformed, and the carbon resistance surface 3
4, it comes into contact with two points with a wide area as shown in FIG. At this time, the current flows as indicated by the dashed arrow in the figure.

Comparing the broken line arrows in FIG. 4 and FIG. 5, it can be seen that the distance of the current passing through the carbon resistance surface 34 is longer in the case shown in FIG. 4, and therefore the resistance between the electric wires 36 and 37 is greater. By measuring this change in resistance value, the capacity of the liquid fuel can be detected.

Next, based on FIG. 1, it will be explained that vertical displacement in the vicinity of the center of the saucer 6 that supports the tank 1 is magnified and appears in the deflection of the spring in the weight sensor 25. As already mentioned, due to the function of the stopper part 22, the tank 1
Almost the entire weight of is supported by the bin 8. As a result, the load can be expressed as a concentrated load near the bin 8.The tank 1, the saucer 6, and this load are added to the weight sensor 25, and a load proportional to the total weight is applied to the weight sensor 25.

Furthermore, if h is the vertical displacement of the supporter of the saucer 6, that is, the vertical displacement of the vicinity of the bottle 8, then the deflection of the spring in the weight sensor 25 is a+b(-)xh. Note that a is the horizontal distance from the fulcrum 24 to the bin 8, and b is the horizontal distance from the bin 8 to the spring 32 of the weight sensor 25.

Therefore, even if the vertical displacement in the vicinity of the center of the tray 6 is small, the spring 33 of the stacked sensor 25 can obtain a large deflection.

Therefore, a weight sensor such as the one in this embodiment or a general potentiometer can be used in this invention. Therefore, there is no need for expensive parts such as amplifiers, which were required in the past.In addition, the vertical displacement near the center of the saucer 6 is small, and therefore the fluctuation in the vertical position of the liquid level of the saucer 6 with respect to the combustion device is small. It is possible to prevent a large impact on the combustion equipment.

In this embodiment, by supporting almost the entire weight of the tank near the pin 8, dimensions a and b can be clarified at step 31, and accurate capacity detection can be performed. However, in other embodiments, the load may not be concentrated near the pin 8 in this way, and a support structure similar to the conventional one may be used. In this case, the exact dimensions of a and b may not be determined at the design stage. Although I don't understand it, I can understand it.

If the transport pipe 9 is made of a hard material and is connected to another combustion device, there is a risk that the receiving tray 6 will be prevented from rotating around the fulcrum bin 24. By connecting 9 to the side where the fulcrum 24 is present,
Alternatively, by making the material of the transport pipe 9 soft, the hindrance to the rotation can be reduced.

Furthermore, in this embodiment, the saucer has a substantially rectangular shape, and the fulcrum pin 24 is provided at one end of the long side, and the spring 33 is provided at the other end, so that the displacement due to the deflection of the spring 33 can be increased. can.

Further, since the packing 23 made of a deformable elastic body is provided in the gap formed between the tank 1 and the receiver 7, it is possible to prevent the liquid fuel in the receiver 6 from evaporating and scattering.

In addition, the spring 33, the carbon resistance surface 34 that forms the sensor, the shorting plate 35, etc. that form the sensor are housed inside the case of the weight sensor, which simplifies the configuration of the device and makes it easy to detect the remaining volume of liquid fuel. Ta.

[Effects of the Invention 1 As described above, according to the present invention, one end of the saucer is pivotally supported, the other end is supported by a spring, and the volume of liquid is detected by detecting the deflection caused by this spring. Even if the displacement in the vertical direction near the center of the saucer is small, the displacement can be increased by the deflection of the spring, and detection can be performed with sufficient accuracy without using a conventional amplifier or the like.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an embodiment of the present invention, FIG. 2 is a partially cutaway front view of FIG. 1, FIG. 3 is a cross-sectional view of the weight sensor 25 shown in FIG. Figure 5 shows the shorting plate 35 in Figure 3.
6 is a partially cutaway front view of the conventional device, and FIG. 7 is a side view of FIG. 6. l... Airtight tank, 2... Cap, 3... Closing valve, 4... Valve seat, 5... Coil spring, 6...
saucer, 7... receiver, 8... bottle, 9... transportation pipe,
10... Fixed leg, 22... Stopper L23.
...Packskin, 24...Fully point bin, 25...Weight sensor, 31...Upper base, 32...Lower base, 33
...Spring, 34...Carbon resistance surface, 35.
...Short circuit board, 36.37...Electric wire. In the drawings, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] an airtight tank that accommodates a liquid, a cap opening at the bottom of the airtight tank, a shutoff valve provided in the cap, and a saucer supporting the airtight tank and having an edge higher than a lower edge of the cap. , a pin fixed to the saucer that pushes up and opens the shut-off valve; a transport pipe for transporting the liquid in the saucer to the outside; a bottom plate that supports the saucer; and one end of the saucer that is horizontally supported with respect to the bottom plate. A liquid tank capacity detection device that includes a fulcrum pin, a spring that supports the other end of the saucer, and a sensor that detects displacement due to the deflection of this spring.