WO2010070758A1

WO2010070758A1 - Liquid quantity detector

Info

Publication number: WO2010070758A1
Application number: PCT/JP2008/073102
Authority: WO
Inventors: 一光温井; 謙一小山; 敏夫鈴木
Original assignee: 日本アプライドフロー株式会社; 株式会社カイジョ－ソニック
Priority date: 2008-12-18
Filing date: 2008-12-18
Publication date: 2010-06-24
Also published as: JP3171135U

Abstract

An impact imparting section (12) consisting of a hammer type electromagnetic coil, and a vibration measuring section (13) having a sensor (13A) are provided integrally in a housing (11). A hammer member (12A) is driven by an electromagnetic coil (12B) to apply an impact to the wall surface of a container (2). Resonance vibration generated in the container (2) by the impact is measured by means of the sensor (13A). A signal processing section (14) analyzes the frequency of resonance vibration based on the output from the sensor (13A) and calculates the residual quantity of liquefied gas in the container (2). The calculation results are displayed on a display section (15).

Description

Liquid level detector

The present invention relates to a liquid amount detection device for detecting a liquid amount (remaining amount) of a liquid remaining in a container.

Liquefied gas is used in various places such as anesthetic laughing gas, sterilization EOG (ethylene oxide gas), and carbon dioxide for fire fighting. The remaining amount of the liquefied gas in the container in use is generally measured by measuring the weight with a scale or using a float type liquid level gauge.

However, the method for measuring the weight requires complicated work such as placing the container on a scale. Further, in the method of reading the display scale of the float type liquid level gauge, only a rough check of the remaining amount has been performed. Therefore, in the past, if the replacement was performed periodically without measuring the remaining amount, or if the display scale indicated that the container was about to become empty, there was actually enough liquid in the container. Even if it remains, the container must be immediately replaced with another new container. As a result, a large amount of liquid remains in the replaced container, and the utilization efficiency of the liquid in the container is deteriorated.

The present invention has been made in view of such problems, and an object of the present invention is to provide a liquid amount detection device capable of easily and accurately confirming the remaining amount of liquid.

The liquid amount detection device of the present invention detects the liquid amount of the liquid in the container. The liquid amount detection apparatus contacts the wall surface of the container with an impact applying unit that applies an impact to the wall surface of the container, and is generated in the container by the impact. A vibration measurement unit that detects resonance vibration, and a liquid amount detection unit that detects the amount of liquid in the container based on the resonance vibration detected by the vibration measurement unit, and at least the impact applying unit and the vibration measurement unit are included in the same housing. It is integrated with the body.

In the liquid amount detection device of the present invention, an impact is applied to the wall surface of the container by the impact applying unit, and the vibration measurement unit measures the resonance vibration generated in the container by the impact through the wall surface of the container. The liquid amount detection unit detects the amount of liquid in the container based on the resonance vibration measured by the vibration measurement unit.

In the liquid amount detection device of the present invention, it is preferable that the impact applying portion includes a hammer member that can project and retract from the housing, and an electromagnetic coil that drives the hammer member with a pulse voltage (or current). Such a configuration makes it possible to apply a constant impact to the wall surface of the container at a constant period.

In addition, by providing the container with a suction portion that can be magnetically attracted to the wall surface of the container on the front surface of the casing, the container can be attached to and detached from the side surface of the container, thereby improving convenience.

In the liquid level detection device of the present invention, a liquid level detection unit may be built in the casing in addition to the impact applying unit and the vibration measurement unit, and further, the liquid level detection unit is detected on the surface of the casing. It is good also as an aspect which provides the display part which displays the amount of liquids.

According to the liquid amount detection device of the present invention, the impact applying unit and the vibration measuring unit are integrally provided in the same housing, the impact applying unit applies an impact to the wall surface of the container, and the impact is generated in the container. Since the resonance vibration is measured by the vibration measuring unit, the remaining amount of liquid can be easily and accurately confirmed.

It is a disassembled perspective view showing the structure of the liquid quantity detection apparatus which concerns on one embodiment of this invention. It is a block block diagram for demonstrating operation | movement of the liquid quantity detection apparatus of FIG. It is a characteristic view showing the relationship between a liquid quantity and a resonant frequency. It is a flowchart for demonstrating the effect | action of a liquid quantity detection apparatus. It is a figure showing the modification of this invention. It is a figure showing another modification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a configuration of a liquid amount detection apparatus 1 according to the first embodiment of the present invention. The liquid amount detection device 1 is for measuring the position of the liquid level S of the liquefied gas L in the container 2 (remaining amount of liquefied gas L), for example.

The container 2 is a vertical container that contains a liquefied gas L such as liquefied oxygen, liquefied nitrogen, or liquefied argon, and is made of, for example, an austenitic stainless steel sheet having sufficient strength and toughness that does not cause brittleness even at ultra-low temperatures. The liquefied gas L is stored in the container 2 under a pressurized state.

The liquid amount detection device 1 includes an impact applying unit 12 and a vibration measuring unit 13 in a housing 11. The housing 11 includes a box-shaped main body 11A having an opening on the upper surface, and a lid member 11B that closes the opening of the main body 11A. A front surface of the housing 11 (a surface facing the container 2) is provided with a through-hole 11a through which a later-described hammer member 12A can project and retreat, and an opening 11b for attaching a later-described sensor 13A.

The impact applying unit 12 is constituted by, for example, a hammer type electromagnetic coil. That is, the impact applying unit 12 includes a hammer member 12A that can project and retract from the through hole 11A of the housing 11, and an electromagnetic coil 12B is wound around the hammer member 12A. For example, when a pulse voltage (or current) is applied to the electromagnetic coil 12B from the voltage source 12C at a constant cycle, the electromagnetic coil 12B is driven, and the hammer member 12A protrudes instantaneously from the housing 11, and the wall surface of the container 2 It will retreat after shocking. The timing of driving the electromagnetic coil 12B is arbitrary, and may be performed whenever necessary, or may be automatically performed at regular intervals. The shape and material of the tip of the hammer member 12A are arbitrary, and the shape may be, for example, a T-shape, and the material may be resin, metal, wood, or the like.

The vibration measuring unit 13 has a sensor 13A. The sensor 13A directly detects the resonance vibration generated in the container 2 due to an impact by bringing the detection portion 13A1 at the tip thereof into contact with the wall surface of the container 2. As this sensor 13A, a sensor such as a stress or pressure can be used in addition to a vibration sensor, an acoustic sensor such as a microphone that detects vibration as sound, a piezoelectric element that detects vibration as distortion. The output signal of the sensor 13A is sent to the signal processing unit 14 in the display device 15 through, for example, the signal cable 13B. The signal processing unit 14 includes a storage unit 14A and a calculation unit 14B.

The storage unit 14A stores specific coefficients a and b corresponding to gas types as described later (Table 1). In the calculation unit 14B, the resonance frequency is obtained based on the resonance vibration measured by the sensor 13A, and the liquefied gas in the container 2 is referred to by referring to a specific coefficient stored in the storage unit 14A by the equation (1) described later. The remaining amount is calculated. The liquid amount (remaining amount) calculated in the calculation unit 14B is digitally displayed on the display unit 15A. Of course, the display on the display unit 15A is not limited to digital display, and may be analog display. Further, the remaining amount data may be transmitted to a place other than the place where the container 2 is installed using a wireless or wired communication means.

The signal processing unit 14 may be built in the housing 11 together with the impact applying unit 12 and the vibration measuring unit 13, and the display unit 15 </ b> A is also provided on the surface of the housing 11, and the display device 15 is integrated with the liquid amount detection device 1. You may make it make it.

A pair of magnets 16 </ b> A and 16 </ b> B are provided on the front surface of the housing 11 as a means for attracting the wall surface of the container 2, and are directly fixed to the wall surface of the container 2 formed of a magnetic material. When the forming material of the container 2 is other than a magnetic material, it may be fixed using a suction type adsorption attachment or a band.

In the liquid quantity detection device 1 of the present embodiment, the liquid quantity is detected according to the following principle. In other words, an impact is applied to the container, the resonance vibration generated in the container is measured with a vibration sensor, the value is analyzed with an FFT (Fast Fourier Transform) analyzer, and the peak value of the frequency is a function of the change in liquid volume. Is plotted as shown in FIG. 3, for example. Based on this result, the remaining amount A of the liquefied gas in the container can be obtained by a linear function of the following equation.
A = a · fnx + b (1)
(Fnx: peak value of resonance frequency, a, b: coefficient specific to each liquefied gas)

In actual measurement, the frequency fnx may vary depending on the material and shape of the container 2 and the mounting position of the liquid amount detection device 1, but the frequency fnx at two points when the container 2 is empty and full is measured in advance. The remaining amount can be measured by inputting.

In the liquid amount detection device 1 of the present embodiment, the remaining amount of liquefied gas in the container 2 can be detected by the following action.

That is, first, the housing 11 is fixed to the wall surface of the container 2 by the

magnets

16A and 16B, and the tip 13A1 of the sensor 13A is brought into contact with the wall surface of the container 2. In this state, in the impact applying unit 12, the electromagnetic coil 12B is driven by applying, for example, a pulse voltage (current) from the voltage source 12C to the electromagnetic coil 12B at a constant cycle. As a result, as shown by the one-dot chain line in FIG. 2, the hammer member 12A instantly protrudes from the housing 11 and gives an impact to the wall surface of the container 2 (FIG. 4, step S101). Due to the impact on the wall surface of the container 21, resonance vibration is generated in the container 2 in accordance with the height of the liquid level S (remaining amount). The resonance vibration is measured by the sensor 13A of the vibration measuring unit 13 through the wall surface of the container 2 (step S102), and the output signal of the sensor 13A is sent to the signal processing unit 14 provided outside the housing 11 through the signal cable 13B. It is done. The signal processing unit 14 analyzes the frequency fnx of the resonance vibration (step S103), refers to the coefficient for each type of gas in the container 2 stored in the storage unit 14B, and stores the inside of the container 2 by the above equation (1). The remaining amount of liquefied gas is calculated (step S104). Next, a digital display or the like of the calculated remaining amount is made on the display unit 15A. Further, this remaining amount data is transmitted as necessary.

As described above, in the liquid amount detection device 1 according to the present embodiment, the impact applying unit 12 is integrated with the casing 11 including the vibration measuring unit 13 to automatically apply the impact to the wall surface of the container 2. Since the resonance frequency is calculated based on the generated resonance vibration and the remaining amount of the liquid is derived based on this resonance frequency, the remaining amount of the liquid can be measured easily and accurately. Thereby, the utilization efficiency of the liquefied gas in the container 2 improves.

Hereinafter, although other embodiments of the present invention will be described, the same components as those of the above-described embodiments will be denoted by the same reference numerals, and description thereof will be omitted.

FIG. 5 shows the configuration of the liquid amount detection apparatus 100 according to the second embodiment of the present invention. This liquid amount detection apparatus 100 is a hammer type as a whole, and enables a measurer to manually apply an impact to the wall surface of the container 2. That is, the casing of the liquid amount detection device 100 is constituted by a main body portion 100A having a striking surface (also a detection surface) 101 at the tip and a gripping portion 100B for a measurer to hold. In the main body 100A, a microphone 102 as the vibration measuring unit 13 is disposed at a position facing the striking surface 101, and a control board 103 for processing an output signal of the microphone 102 is provided. The control board 103 corresponds to the signal processing unit 14 of the above embodiment. A display unit 15 for displaying measurement results is provided on the front surface of the main body 100A, together with various setting switches 104 for inputting coefficients a and b for each gas type. A battery 105 for driving the microphone 102 and the control board 103 is built in the gripper 100B, and a measurement start switch 106 is provided on the front surface.

In the liquid amount detection device 100 according to the present embodiment, the measurer manually strikes the striking surface 101 against the side surface of the container 2 and directly causes the striking surface (also detecting surface) 101 to come into contact with the wall surface, thereby generating resonance. The vibration is received as a sound wave by the microphone 102 and output to the control board 103 as an electric signal. The control board 103 calculates the liquid amount (remaining amount) by the same process as in the above embodiment, and displays the result on the display unit 15.

Thus, in this embodiment, the configuration is simpler than the above embodiment, and it is convenient for carrying.

A liquid amount detection device 200 shown in FIG. 6 has an impact applying portion 12 using an electromagnetic coil shown in FIG. 1 built in the tip portion of the liquid amount detection device 100 shown in FIG. With such a configuration, it is possible to always apply an impact to the wall surface of the container 2 with the same strength. In addition, you may make it curve the contact part with the container 2 of the liquid quantity detection apparatus 200 so that the wall surface of the container 2 may be followed.

As described above, the present invention has been described with reference to the respective embodiments, but the present invention is not limited to these, and various modifications are possible. For example, in the above embodiment, the case where the present invention is applied to the measurement of the remaining amount of the gas cylinder type container 2 has been described. However, the present invention is not affected by the shape of the container or the structure existing in the container. It can be applied to any type of container. Further, the display unit 15 may display the usage amount instead of the remaining amount.

Claims

A liquid amount detection device for detecting the amount of liquid in a container,
An impact imparting portion for impacting the wall surface of the container;
A vibration measuring unit that contacts a wall surface of the container and detects resonance vibration generated in the container by an impact;
A liquid amount detection unit that detects a liquid amount in the container based on the resonance vibration detected by the vibration measurement unit;
And a liquid material detecting device having at least the impact applying unit and the vibration measuring unit integrally in the same housing.
The liquid amount detection device according to claim 1, wherein the impact applying unit includes a hammer member that can project and retract from the housing, and an electromagnetic coil that drives the hammer member with a pulse voltage.
The liquid amount detection device according to claim 1, further comprising an adsorption portion that can be adsorbed to a wall surface of the container on a front surface of the housing, and detachable from a side surface of the container.
The liquid quantity detection device according to claim 1, wherein the liquid quantity detection unit is built in the housing.
The liquid amount detection device according to claim 1, further comprising a display unit that displays a liquid amount detected by the liquid amount detection unit on a surface of the housing.