JP3362916B2 - Liquid volume measurement device - Google Patents

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid amount measuring device for measuring the volume of liquid flowing into a cylinder.

[0002]

2. Description of the Related Art Conventionally, the volume expansion coefficient of a rubber hose has been measured by filling the rubber hose with a liquid such as oil and detecting the amount of change of the liquid in the rubber hose with respect to temperature change or pressure change. At this time, the amount of change of the liquid in the rubber hose is measured by the liquid amount measuring device.

FIG. 2 is a configuration diagram of a main portion showing an example of the above-described volume expansion coefficient measuring device. In the figure, 1 is a rubber hose to be measured, 2 is a pressurizing device, 3 and 4 are measuring valves,
5 is a liquid amount measuring device. One end 1a of the rubber hose 1 is connected to the pressurizing device 2 via the measuring valve 3, and the other end 1b is connected to the liquid amount measuring device 5 via the measuring valve 4.

The liquid amount measuring device 5 has a liquid flow port 6 on its lower surface.
It consists of a graduated cylinder 6 having a, and a flow port 6a is connected to the measurement valve 4.

According to the above-mentioned structure, when measuring the volume expansion amount of the rubber hose 1, the measuring valves 3 and 4 are opened, the rubber hose 1 is filled with the liquid by the pressurizing device 2, and the graduated cylinder is used. 6 is filled with the liquid up to a predetermined position, the measurement valve 4 is closed, and the rubber hose 1 is pressed by the pressurizing device 2.
The pressure of the liquid filling the inside is changed to a predetermined pressure under a prescribed pressure increase condition. Then, after the pressure of the liquid in the rubber hose 1 is maintained for a predetermined time, the measurement valve 3 is closed and the measurement valve 4 is opened. As a result, the liquid pressure in the rubber hose 1 is released and becomes equal to the ambient air pressure, so that the rubber hose 1 contracts and the liquid amount in the graduated cylinder 12 changes. After the elapse of the specified time, the measurement valve 4 was closed and the increase in the liquid amount in the graduated cylinder 12 was visually measured.

The above-mentioned measurement of the volume expansion amount is usually carried out at room temperature, but in order to examine the temperature dependence of the expansion amount, the volume expansion amount may be measured by using a measuring device with a constant temperature bath.

[0007]

However, in the above-mentioned liquid amount measuring device 5, since the liquid amount in the graduated cylinder 6 is visually read, a reading error often occurs due to the influence of individual differences. It was not possible to make accurate measurements.

Further, in order to reduce the reading error, FIG.
The liquid amount measuring device 9 provided with the cylinder 8 with the potentiometer 7 as shown in FIG. As is well known, the potentiometer 7 changes the resistance value in response to a mechanical change amount, and in the liquid amount measuring device 9, the piston 8a moves in accordance with the liquid amount in the cylinder 8, Accordingly, the movable piece 7a of the potentiometer 7 connected to the piston 8a slides along the resistor 7b. This allows the movable piece 7a to correspond to the amount of movement of the piston 8a.
Since the resistance value between the resistance and the one end of the resistor 7b changes, the liquid amount in the cylinder 8 can be detected by reading this resistance value.

However, even in the liquid amount measuring device 9 provided with the potentiometer 7 described above, the reading error could not be kept within the allowable value. That is, a mechanical sliding resistance is generated between the cylinder 8 and the piston 8a and between the movable piece 7a and the resistor 7b, which causes an error.

In view of the above problems, an object of the present invention is to provide a liquid amount measuring device capable of automatically measuring the amount of liquid in a cylinder with a low error.

[0011]

In order to achieve the above-mentioned object, the present invention provides a cylinder having a liquid flow port, which is a measurement object, at a lower portion thereof, and a vertically extending cylinder having an upper portion thereof opened. A liquid amount measuring device for measuring the amount of liquid flowing into the cylinder, wherein the float floats on the liquid surface in the cylinder and has a horizontal light-receiving surface of a predetermined area, and is arranged above the opening of the cylinder. ,
A laser light generation unit that irradiates a laser beam toward the light receiving surface of the float, and a laser beam disposed above the opening of the cylinder, and detects the position of the float based on the laser light diffused from the light receiving surface of the float. position detecting means for, based on a detection result by said position detecting means, a calculating means for calculating the amount of liquid in the cylinder, and output means for outputting the calculation result of the calculating means is provided, the flow
The outer diameter of the upper surface of the port is slightly smaller than the inner diameter of the cylinder.
The outer diameter of the lower surface is smaller than the outer diameter of the upper surface.
An annular float with a tapered outer peripheral surface
A floating body and having the light receiving surface on the upper surface, which is fixed on the floating body
We propose a liquid amount measuring device that is composed of a light receiving plate .

According to a second aspect of the present invention, in the liquid amount measuring device according to the first aspect, the position detecting means is the float.
The laser light diffused from the light receiving surface of the
Has means to receive light at different positions corresponding to changes in
The calculation means is the position detection means when measuring the liquid amount.
Based on the receiving position of the diffused laser light
A liquid amount measuring device having means for calculating the amount of change in the liquid in the cylinder is proposed.

[0013]

According to the first aspect of the present invention, when the liquid flows into the cylinder, the float floats on the surface of the liquid,
The float moves up and down in response to changes in the amount of liquid in the cylinder. Further, the laser light generator irradiates the light receiving surface of the float with laser light, and the position detecting means detects the position of the float based on the laser light diffused from the light receiving surface. Further, based on the position of the float detected by the position detection means, the calculation means calculates the amount of liquid in the cylinder, and the calculation result is output by the output means.
Therefore, it is possible to detect the amount of liquid in the cylinder without contact with the laser light.

Further, the float of said annular, and the float from the light receiving plate having a light-receiving surface to the upper surface is fixed is configured on該浮Agetai. Here, since the levitation body has an annular shape, its buoyancy acts in an annular shape, and the distance between the center of gravity of the levitation body and the center of the buoyancy is increased when the levitation body is in an unstable state. be able to.

Further, the outer diameter of the float is a cylinder.
It is set to be slightly smaller than the inner diameter of
Inside the cylinder because the outer circumference is tapered
The surface tension of the liquid can be used, which allows
The cylinder and flow as the float moves when the liquid level changes.
Stability of the float while eliminating sliding resistance with the float
The flexibility is increased and the float moves smoothly.

According to a second aspect, the position detecting hand is
The steps allow the laser diffused from the light receiving surface of the float.
The light has different positions corresponding to the vertical change of the liquid surface.
Is received by the calculation means based on the light receiving position.
From this, the change amount of the liquid in the cylinder is calculated.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing a main part of an expansion coefficient measuring device for a rubber hose using the liquid amount measuring device of the present invention. In the figure, the same components as those of the above-described conventional example are designated by the same reference numerals and the description thereof will be omitted. Further, a difference between the conventional example and the present embodiment is that the liquid amount measuring device 11 using a laser beam is provided.

The liquid amount measuring device 11 includes a measuring cylinder 12
The float 121, the laser displacement meter 13 arranged above the graduated cylinder 12, and a calculation display unit 14 for calculating and displaying the displacement amount of the float 121 as a liquid amount.

The graduated cylinder 12 has a predetermined inner diameter, has a liquid flow port 12a formed in a lower portion thereof, and has a cylindrical shape with an open upper surface, and has a float 12 inside thereof.
1 is provided. As shown in the plan view of FIG. 4 (a) and the side sectional view of FIG. 4 (b), the float 121 includes a float 122 made of, for example, an annular foamed resin having a predetermined thickness,
It is composed of a thin circular light receiving plate 123 fixed to the upper surface of the levitation body, and the outer diameter of the upper surface of the levitation body 122 is equal to that of the measuring cylinder 1.
It is formed to be slightly smaller than the inner diameter of 2. Further, the outer peripheral surface of the floating body 122 is formed in a tapered shape, and the outer diameter of the lower surface is smaller than the outer diameter of the upper surface. Furthermore, the light receiving plate
The outer diameter of 123 is formed to be equal to the outer diameter of the upper surface of the levitation body 122, and the upper surface of the light-receiving plate 123 has a color that makes it easy to identify the irradiation position of laser light, which will be described later. A through hole 124 for removing air is formed at a predetermined position.

As shown in FIG. 5, the laser displacement meter 13 is composed of a laser light irradiation section 131 made of a semiconductor laser, a lens 132, and a photodetector 133 made of a one-dimensional CCD.

The laser light emitting section 131 is arranged at a position where the emitted light can be vertically irradiated onto the upper surface of the light receiving plate 123 of the float 121 in the graduated cylinder 12. Also, the lens 13
2 and the photodetector 133 are connected to the light receiving plate 123 by the lens 132.
The irradiation position A of the upper laser light is arranged at a position where an image can be formed on the photodetector 133, and the image forming position B on the photodetector 133 moves on the CCD element in response to the vertical movement of the float 121. Is set to.

The operation display unit 14 inputs the output signal of the photodetector 133, detects the image forming position B corresponding to the irradiation position A of the laser beam, and the float 12 from this image forming position B.
It calculates a first position, calculates the liquid amount of the graduated cylinder 12, and displays the computation results.

Next, the operation of this embodiment having the above-mentioned structure will be described with reference to FIGS. When measuring the volume expansion amount of the rubber hose 1 with respect to the pressure, the measurement valve 3 and the measurement valve 4 are opened, the rubber hose 1 is filled with the liquid by the pressurizing device 2, and the liquid is brought to a predetermined position of the graduated cylinder 12. Fulfill. Next, the measurement valve 4 is closed, and the reset button of the operation display 14 sets the present position of the float 121 as the origin. After that, the pressure of the liquid filled in the rubber hose 1 is changed by the pressurizing device 2 to a predetermined pressure under a prescribed pressure increase condition. Next, after the liquid pressure of the rubber hose 1 is maintained for a predetermined time, the measurement valve 3 is closed and the measurement valve 4 is opened in this order. As a result, the hydraulic pressure in the rubber hose 1 is released and becomes equal to the atmospheric pressure of the surroundings, so the rubber hose 1 expanded by the hydraulic pressure contracts, and the expanded volume of liquid flows from the rubber hose 1 into the graduated cylinder 12. As a result, the amount of liquid in the measuring cylinder 12 increases. At this time, the float 121 in the measuring cylinder 12 rises as the amount of liquid in the measuring cylinder 12 increases. After the lapse of the specified time, the measurement valve 4 is closed. Then float from the origin
The displacement amount of 121 is taken into the calculation display device 14 and displayed as the volume expansion amount.

For example, with the rubber hose 1 attached, the light receiving plate 12 of the float 121 in the graduated cylinder 12
Fill the liquid until the upper surface of 3 reaches the position of L1 in the figure.
At this time, the air existing in the central portion of the floating body 122 of the float 121 is discharged through the through hole of the light receiving plate 123, and the buoyancy on the float 121 is evenly applied to the annular floating body 122.
The light receiving plate 123 is held in a horizontal state. Here, as shown in FIG. 5, laser light is irradiated to point A on the upper surface of the light receiving plate 123, and this irradiation position A is detected by the photodetector 133 via the lens 132.
An image is formed at the upper point B.

After that, by performing the above-mentioned operation, as the rubber hose 1 contracts, a volume of liquid expanded by hydraulic pressure flows into the graduated cylinder 12, and the upper surface of the light receiving plate 123 of the float 121 is positioned at the position L2. Rise to.

Here, the outer diameter of the float 121 is set to be slightly smaller than the inner diameter of the graduated cylinder 12, and in order to utilize the surface tension of the liquid in the graduated cylinder 12, the outer circumference of the float 122 is tapered. It is being processed. As a result, when the float 121 moves when the liquid level changes,
The sliding resistance between the graduated cylinder 12 and the float 121 is eliminated, and the stability of the float 121 is increased.
Can be moved smoothly.

When the upper surface of the light receiving plate 123 of the float 121 reaches the position of L2, the irradiation position of the laser light moves to A ',
The image forming position of the irradiation position A ′ on the photodetector 133 moves to the point B ′. As a result, the difference between the detection positions from the image formation position B on the photodetector 133 to the image formation position B ′ is calculated and displayed on the calculation display 14
And the displacement amount of the float 121 is detected. The liquid amount is calculated and displayed by multiplying this displacement amount by the known inner diameter of the graduated cylinder 12.

Therefore, the amount of liquid in the graduated cylinder 12 can always be measured accurately without being affected by individual differences, so that an accurate amount of expansion can be obtained.

In addition, the float 121 is used when the rubber hose 1 and the liquid inside the rubber hose 1 are heated to a high temperature.
It prevents steam from rising from the liquid in 2. As a result, the liquid in the measuring cylinder 12 is not lost as steam, and the amount of liquid in the measuring cylinder 12 can be accurately measured.

The configuration of this embodiment is an example, and the present invention is not limited to this. For example, in this embodiment, the position of the float 121 is detected by detecting the image forming position B on the photodetector 133 corresponding to the laser light irradiation position A.
The amount of liquid in the graduated cylinder 12 may be detected from the time until the light reflected by the light receiving plate 123 returns using a laser pulse.

Although almost the same measurement can be performed by using ultrasonic waves instead of laser light, when ultrasonic waves are used, the propagation speed of the acoustic waves changes due to temperature changes in the air, and measurement errors occur. Occurs, and the measurement accuracy decreases as compared with the case of using a laser beam, which is not practical.

In this embodiment, one through hole 124 is formed at the center of the float 121, but one or more through holes 124 may be formed, and the through hole 124 may be formed anywhere as long as it does not hinder the detection of the laser beam irradiation position. You may.

[0033]

As described above, according to the first aspect of the present invention, the position of the float in the cylinder is detected by a laser beam in a non-contact manner, and the liquid amount in the cylinder is detected based on the detected position of the float. Is calculated, the measurement error can be significantly reduced as compared with the conventional case. further,
Since the irradiated light on the float is received, without that the irradiation light is transmitted into the liquid, it is possible to improve the measurement accuracy.

Furthermore, by utilizing the relationship between the center of gravity of the float body forming the float and the position of the buoyancy and the surface tension of the liquid in the cylinder, the upper surface of the float can be always kept horizontal. . As a result, it is possible to significantly reduce the detection error due to the angle variation of the light receiving surface of the float.

According to claim 2, in addition to the above effects.
By the position detecting means, the light receiving surface of the float is
As a result, the diffused laser light will not respond to changes in the vertical direction of the liquid surface.
The light is received at different positions depending on the
The amount of change in the liquid in the cylinder is calculated by the calculation means
Therefore, the measurement accuracy can be further improved.
It

[Brief description of drawings]

FIG. 1 is a main part configuration diagram showing a volume expansion coefficient measuring device according to an embodiment of the present invention.

FIG. 2 is a main part configuration diagram showing an example of a conventional volume expansion coefficient measuring device.

FIG. 3 is a main part configuration diagram showing another conventional example.

FIG. 4 is a diagram showing a float according to an embodiment of the present invention.

FIG. 5 is a view for explaining the operation of the liquid amount measuring device according to the embodiment of the present invention.

[Explanation of symbols]

1 ... Rubber hose, 2 ... Pressurizing device, 3,4 ... Measuring valve, 11
... Liquid amount measuring device, 12 ... Measuring cylinder, 121 ... Float, 122 ... Floating body, 123 ... Light receiving plate, 124 ... Through hole, 13
... Laser displacement meter, 131 ... Laser light irradiation part, 132 ... Lens, 133 ... Photodetector, 14 ... Calculation display.

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Claims (2)

(57) [Claims] 1. A liquid amount measuring device for measuring the amount of liquid flowing into the cylinder, comprising a vertically extending cylinder having an opening for liquid to be measured in the lower part and having an opening in the upper part, A float having a horizontal light-receiving surface of a predetermined area floating on the liquid surface in the cylinder, and a laser light generator disposed above the opening of the cylinder and irradiating laser light toward the light-receiving surface of the float, Position detecting means arranged above the opening of the cylinder for detecting the position of the float based on the laser light diffused from the light receiving surface of the float, and the cylinder based on the detection result by the position detecting means. calculating means for calculating the amount of liquid in the inner, provided and output means for outputting an operation result of said arithmetic means, said float, the upper surface OD Siri Than the inner diameter of Zehnder
The outer diameter of the lower surface is slightly smaller than that of the upper surface.
Has a tapered outer peripheral surface set smaller than the outer diameter
And an annular levitation body that is fixed on the levitation body
A liquid amount measuring device comprising a light receiving plate having a light receiving surface . 2. The position detecting means receives the float.
The laser light diffused from the light surface is changed in the vertical direction of the liquid surface.
The position detecting means at the time of measuring the liquid amount.
Based on the receiving position of the diffused laser light by
The liquid amount measuring device according to claim 1, further comprising means for calculating a change amount of the liquid in the cylinder . [0001]