JPH0519921U - Liquid volume indicator - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a liquid volume indicator which can be miniaturized and which is capable of high precision and wide range measurement. A photocell 107 moved by a linear motor 109 outputs a light reception signal when it receives light from a laser 103 reflected by a mirror 106 on a float 105, and a detector 112 responds to the light reception signal by a photoreception signal. The position of the cell 107 is detected. Since the position of the photocell 107 corresponds to the liquid surface, the remaining amount of liquid is measured.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a liquid amount indicating device for detecting the remaining amount of liquid such as oil and water.

[0002]

[Prior Art]

 Conventionally, various liquid volume indicating devices have been used to detect the remaining amount of liquid such as oil and water. FIG. 4 shows an example of a conventional liquid volume indicating device. In FIG. 4, oil 402 stores oil 402. A liquid volume instruction transmitting device 403 is arranged in the oil tank 401. The float 404 floating on the oil surface can move up and down along the two float guide rods 405. A stainless wire 406 is connected to the upper part of the float 404. The stainless wire 406 is connected to the weight 409 via a guide pulley 407 and a main pulley 408. The weight 409 is arranged so as to be vertically movable within a hollow guide pipe 410 whose lower portion and side surfaces are hermetically sealed. A potentiometer (not shown) whose resistance changes according to the rotation of the main pulley 408 is coupled to the main pulley 408.

When the amount of oil changes and the oil level goes up and down, the float 404 moves up and down following this. In response to the vertical movement of the float 404, the stainless wire 406 and the weight 409 move up and down, and the main pulley 408 rotates in the X or Y direction due to the friction with the stainless wire 406. Since the resistance value of the potentiometer changes according to the amount of rotation of the main pulley 408, an analog signal corresponding to the height of the oil level can be obtained from the potentiometer. Therefore, the height of the oil surface can be measured by detecting the output signal of the potentiometer with a detector (not shown).

[0004]

[Problems to be solved by the device]

 It is possible to detect the remaining amount of liquid by the liquid amount indicating device described above. However, in order to perform highly accurate detection, a reduction mechanism for transmitting the rotation of the large main pulley 408 and the main pulley 408 to the potentiometer is necessary, and in order to prevent the measurement error due to the weight of the stainless steel wire 406 from occurring. In addition, a large float 404 having a large buoyancy is required, which causes a problem that the device itself becomes extremely large and expensive. Further, since the pulley and the stainless wire are used, there is a problem that the stainless wire is vulnerable to vibration and easily disengaged from the pulley due to an earthquake or the like, and the stainless wire slips to make an accurate measurement. Furthermore, there are problems that many mechanical parts such as gears and other speed reduction mechanisms are prone to failure, or that potentiometers are vulnerable to electrical surges and are easily damaged.

As another liquid amount indicating device, there has been proposed a device in which a gauge having a bar code is placed on the float and is read by a bar code scanner (see Japanese Utility Model Laid-Open No. 1-146128). However, in this method, since the barcode is formed by printing, there is a problem that the barcode may disappear or be blurred due to aging, making it difficult to perform highly accurate measurement. Moreover, since a long gauge is required for a wide range of measurement, there is a problem that the device itself becomes large.

On the other hand, the remaining amount of the liquid is measured by placing a light-transmitting medium having a different amount of light transmission on the float and detecting the amount of light from the light source obtained through the light-transmitting medium. There is known a liquid amount indicating device configured to do so (see Japanese Patent Laid-Open No. 1-219619). However, this method has a problem that it is difficult to precisely prepare a light-transmitting medium having a predetermined shape such as a triangle, and it is difficult to perform high-precision measurement. In addition, since a long light-transmitting medium is required to measure a wide range, there is a problem that the device itself becomes large.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid volume indicator which can be miniaturized, and which can perform high precision and wide range measurement.

[0008]

The liquid volume indicator of the present invention comprises a float that moves along a guide to detect a change in the liquid volume in a tank, and the liquid volume is detected by detecting the position of the float. In the liquid amount indicating device, the light reflecting member placed on the float, the light source unit that emits light to the light reflecting member, and the light source unit reflected by the light reflecting member. A light receiving unit that receives light and outputs a light receiving signal, a moving unit that moves the light receiving unit along the guide, and a detection unit that detects the position of the light receiving unit in response to the light receiving signal are provided. It is characterized by being.

[0009]

[Action]

 The light receiving section is moved along the guide by the moving section, and when the light receiving section receives the light from the light source section reflected by the reflecting member and outputs the light receiving signal, the detecting section responds to the above light receiving signal and The position of the light receiving part is detected. The position of the light receiving portion corresponds to the liquid surface.

[0010]

【Example】

 1 is a front view showing an embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA. In FIGS. 1 and 2, a light source support portion 102 is provided on the upper portion of a cylindrical glass tube 101 as a guide, and a liquid entry portion 104 having an opening at the lower end is provided on the lower portion. Inside the light source supporting portion 102, a semiconductor laser 102 as a light source portion is arranged. The laser 103 emits light along the length direction of the glass tube 101. A float 105 is arranged in the glass tube 101 so as to be vertically movable. The two recesses provided in the float 105 are engaged with the protrusions 111 provided in the lengthwise direction of the inner wall of the glass tube, and the float 105 is restricted from rotating and can only move up and down. ing. A mirror 106 as a reflecting member is fixed on the float 105 at a predetermined angle, and reflects the light from the laser 102 in a perpendicular direction.

On the other hand, a linear motor 109 is arranged along the glass tube. The linear motor coil 108 is provided with a photocell 107 as a light receiving portion at a position facing the mirror 106. The photocell 107 is connected to an ultrasonic length measuring device 112 as a detection unit. The operation of the liquid quantity indicating device configured as described above will be described below.

Now, it is assumed that the liquid quantity indicating device is arranged in an oil tank (not shown), the oil 110 penetrates into the glass tube 101 from the liquid penetrating portion 104, and the float 105 is at the position shown in FIG. . When an instruction to measure the amount of oil is given by a control device (not shown) such as a computer, light is emitted from the laser 103 toward the mirror 106. This light is reflected at a right angle by the mirror 106, passes through the glass tube 101, and advances toward the linear motor 109.

On the other hand, the linear motor coil 108 moves from the lower end of the glass tube 101 in the direction of the arrow. Upon receiving the light, the photocell 107 outputs a light reception signal. In response to the received light signal, the detector 112 emits ultrasonic waves to detect the position of the photocell 107. Since the position of the photocell corresponds to the oil level, it means that the position of the oil level could be measured.

As described above, according to this embodiment, the photocell 107 has a configuration in which the detector 112 detects the position where the light from the laser 103 reflected by the mirror 106 is received. It does not use elements such as media that require precision, and has a simple configuration that enables highly accurate measurement. Further, the mirror 106 mounted on the float 105 only needs to have a size capable of reflecting light, so that the size can be reduced and a wide range of measurements can be performed.

In particular, since the depression of the float 105 is engaged with the protrusion 111, the float 105 has a structure in which it does not rotate, and therefore the mirror 106 does not rotate, so that the light from the laser 103 can be reliably received. In addition, the light can be reflected in the direction of the photocell 107, and accurate measurement is possible. In addition, since the size can be reduced as described above, it can be easily attached to the liquid level gauge outside the liquid tank, and inspection and maintenance are easy. Furthermore, when installing and replacing the existing tank, this device can be performed for each device, which facilitates on-site installation and replacement work.

In this embodiment, in order to move the photocell, a linear motor that can be downsized and can be moved at high speed is used, but it is also possible to use a rotary motor and a rack gear. FIG. 3 is a partial sectional view showing another embodiment of the present invention. In FIG. 3, the glass tube 101 has a rectangular cross section, and the float 105 has a rectangular shape slightly smaller than the inner wall of the glass tube 101. With such a shape, the rotation of the float 105, that is, the rotation of the mirror 106 can be prevented and only the vertical movement can be performed, and the light from the laser can be reliably reflected in the photocell direction.

[0017]

[Effect of the device]

 According to the present invention, the reflecting member is placed on the float, and the position of the light receiving unit that receives the light from the light source unit reflected by the reflecting member is detected by the detecting unit. High precision and wide range measurement is possible. In addition, since it can be downsized, it can be attached to the liquid level gauge outside the liquid tank, facilitating inspection and maintenance. In addition, when installing and replacing in an existing tank, this device can be performed for each device, which facilitates on-site installation and replacement work.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

2 is a sectional view taken along line AA of the embodiment of FIG.

FIG. 3 is a partial cross-sectional view showing another embodiment of the present invention.

FIG. 4 is a front view of a conventional liquid volume instruction transmitting device.

[Explanation of symbols]

 101-Glass tube 102-Light source support 103-Laser 104-Liquid intrusion 105-Float 106-Mirror 107 ... Photocell 108 ... Linear motor coil 109 ... Linear motor 110 ... Oil 111 ... Protrusion 112 ... Detector

Claims (1)

[Scope of utility model registration request] 1. A liquid quantity indicating device comprising a float which moves along a guide for detecting a change in the liquid quantity in a tank, and which indicates a liquid quantity by detecting the position of the float, wherein: A mounted light reflecting member, a light source unit that emits light to the light reflecting member, a light receiving unit that receives the light from the light source unit reflected by the light reflecting member and outputs a light receiving signal, and the light receiving unit A liquid amount indicating device comprising: a moving unit that moves the unit along the guide; and a detection unit that detects the position of the light receiving unit in response to the light receiving signal.