JPH02281109A - Method and apparatus for detecting liquid height - Google Patents

Abstract

PURPOSE:To detect the height of liquid in a container efficiently and accurately by projecting a light beam from one side of the light transmitting container, and receiving the light at the upper end of a high luminance part of the light caused by the lens effect of the liquid in the container at the other side of the container. CONSTITUTION:A container 1 filled with liquid 2 is conveyed by a container conveyer 6. When said container 1 is conveyed to the front part of an photoelectric switch 4, the switch 4 becomes a light shielded state. The detected signal of the switch 4 is inputted into a control mechanism 7. A timer in the mechanism 7 is operated. When, the center of the container 1 is moved to the position of a light source 3, the light beam from the light source 3 forms a high luminance part 5 of the light by the lens effect of the liquid 2 in the container 1. When the liquid level of the liquid 2 is higher than a reference, the light at an upper end 5a of the high luminance part 5 is inputted into the switch 4. The detected signal caused by the incident light is sent into the mechanism 7. The mechanism 7 is not operated, and the timer is reset. Then the liquid level of the liquid 2 is lower than the reference, the light at the upper end 5a is not inputted into the switch 4. When the timer reaches a specified time, the mechanism 7 is operated, and an alarm is issued.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to pharmaceutical products in translucent containers such as glass bottles,
The present invention relates to a method and device for accurately detecting the liquid level of foods, cosmetics, etc.

(Prior art and its problems) Various methods have been proposed to detect the liquid level in a container. For example, X-rays are projected from the side of the container and the difference in the amount of absorbed How to measure and JP-A-60
- As proposed in Publication No. 66121, there is a method of emitting ultrasonic waves from the side of the container and measuring the presence or absence of reflection of the ultrasonic waves depending on the presence or absence of liquid, and a light source on one side of the container and a light-blocking function on the other side. A transmission type photoelectric switch having a liquid C is provided.
) There is a method that takes advantage of the fact that light is blocked by the presence of light.

However, the method using X-rays has the disadvantage that handling is complicated. Furthermore, the method using ultrasonic 2iK has the drawback that in the case of a foaming liquid, the ultrasonic waves are diffusely reflected, making accurate measurement impossible. Furthermore, in the method using a photoelectric switch having the function of turning on when light is blocked, when a colored layer is used,
There is a drawback that measurements cannot be performed because the effect of light shielding due to the effect of the colored layer is greater than the presence or absence of liquid.

In order to solve one of these problems,
Publication No. 37 states that electromagnetic waves are projected from the bottom of the container, the electromagnetic waves diffusely reflected on the liquid surface in the container are received, and of the diffusely reflected electromagnetic waves, only the electromagnetic waves reflected in the permissible direction reach the receiver. A liquid level detection device configured to restrict the direction has been proposed, but it requires a hole to be provided on the bottom of a belt conveyor, etc. to project electromagnetic waves from the bottom of the container, making it difficult to install it easily on conventional equipment. There was a problem.

Although various methods for detecting the liquid level in a container have been proposed, there is no simple method for detecting the liquid level that can be applied even when the liquid in the container is foaming and the container has a colored layer. , the emergence of a highly accurate method for detecting the liquid height in a container has been desired.

The present invention has been made in view of the above-mentioned problems, and includes:
The object of the present invention is to provide a method and device that can easily, efficiently, and accurately detect the liquid level of a liquid in a container.

(Means for solving the problems) In order to achieve the above-mentioned object, the present invention has the following configuration.

That is, in the first invention, a light beam is irradiated toward the container from one side of the translucent container, and the light from the upper end of the high-intensity part created by the lens action of the liquid in the container is transmitted to the other side of the container. The gist of the invention is a liquid level detection method characterized by receiving light at the side of the liquid. A light source placed on one side of the container that emits a light beam toward the photosensitive container, a transmission type photoelectric switch placed on the other side of the container, and a timer started by a detection signal generated by shielding the photoelectric switch. , and a control device that operates when a detection signal due to light input to the photoelectric switch is not detected before the timer reaches a predetermined time, and the light beam from the light source is irradiated onto the container, and the liquid in the container is The gist of the present invention is a liquid level detecting device characterized in that the photoelectric switch is arranged so that the light from the upper end of the high-intensity portion of the photoelectric light produced by the lens action of the photoelectric switch is received by the photoelectric switch.

(Function) The present invention irradiates a light beam toward the container from one side of the translucent container, and generates photoelectric charges due to the lens action of the liquid in the container. Since the light from the top of the high-brightness area (not possible) is received on the other side of the container, if the liquid level is below a specified level,
Since the light at the upper end of the high-brightness section is not received, containers with insufficient liquid height can be easily detected.

(Example) Next, the present invention will be explained in detail based on examples.

FIG. 1 is a schematic diagram of an apparatus for carrying out the method of the present invention, in which (1) is a translucent container made of, for example, a colored layer, and an appropriate liquid (2) is contained in this container. The containers are filled and serve as machine grooves that are sequentially transported by a container transport device (6) such as a belt conveyor.

(3) is a light source disposed in all cases in the container (1), and this light source (3) may be, for example, a halogen lamp, an incandescent lamp,
It consists of laser light, etc. (4) is the above container (1
) is a well-known transmission type photoelectric switch placed on the other side of the switch, and although the internal illustration is omitted, it includes a light-receiving section that has a light-receiving element that derives a photocurrent in response to light from a light source, and It has a processing circuit that receives the signal and outputs a detection signal. And the photoelectric switch (4) is
When the liquid level of the liquid (2) in the container (1) is at the reference level, the uppermost end (6a) of the photoelectric high-intensity part (5) formed by the lens action of the liquid (2) in the container (1) It is located at a position where it can receive light.

Further, the photoelectric switch (4) includes the photoelectric switch (4).
), the timer is started by the detection signal caused by the shading of
And the photoelectric switch (
A control device (7) is connected which is activated when the detection signal of 4) is not detected.

Next, the method of the present invention carried out using the above-mentioned apparatus will be explained.

As shown in FIG. 2, first, a container (1) filled with a liquid (2) is transferred to a container conveying device (6) such as a belt conveyor.
). When the container (1) is in the position (a), the photoelectric switch (4) is in the light receiving state, and when the container (1) moves to the position (b), the photoelectric switch (4) is in the light receiving state.
4) is in a light-shielded state, a detection signal from the photoelectric switch (4) is input to the control mechanism (7), and a timer in the control mechanism (7) is activated. When the container (1) further advances to the position of
5).

When the liquid level of the liquid (2) in the container (1) is above the standard, the upper end (5a) of the high brightness part (5) of the photoelectric is illuminated by the photoelectric switch (4), and the timer is activated for a predetermined time. Since a detection signal due to the incident light is sent to the control device (7) before reaching the point, the control device (7) does not operate and the control mechanism (7)
The timer inside will also be reset.

On the other hand, if the liquid level of the liquid (2) in the container (1) is below the standard, the upper end (5a) of the high-brightness part (5) of the photoelectric is not illuminated by the photoelectric switch (4), and the timer is set to a predetermined value. When the time is reached, no detection signal due to incident light is detected, so the control device (7) is activated, for example, to issue an alarm or to discharge liquids whose liquid level is below the standard from the system.

The predetermined time of the timer is determined by the speed of the conveyor (6) such as a belt conveyor and the radius of the container (1), and is determined by the radius of the container (am) ÷ the speed of the conveyor (am/
Needless to say, it is sufficient to set the length slightly longer than 5ea).

(Effects of the Invention) As detailed above, according to the present invention, even when the liquid in the container is foamable and the container is a colored bottle, the height of the liquid in the container can be detected easily, efficiently, and accurately. This has the effect that an unmanned system can tell if there is an excess or deficiency in the contents.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of an apparatus for carrying out the method of the present invention.
FIG. 2 is a schematic diagram showing the operating state, and FIG. 3 is a detailed explanatory diagram of the present invention. Explanation of symbols (1)...Container, (2)...Liquid, (
3)...Light source, (4)...Photoelectric switch, (5)...High brightness section, (6)...Transport device 1° (7)...Control mechanism.

Claims (1)

[Claims] 1) A light beam is irradiated toward the container from one side of the translucent container, and the light from the upper end of the high-intensity part created by the lens action of the liquid in the container is directed toward the container. A liquid height detection method characterized by receiving light on the other side. 2) A light source placed on one side of the container that emits a light beam toward the moving translucent container, a transmission photoelectric switch placed on the other side of the container, and a detection signal generated by blocking light from the photoelectric switch. and a control device that starts a timer and operates when a detection signal due to light input to the photoelectric switch is not detected by the time the timer reaches a predetermined time, and the light beam from the light source is irradiated onto the container. . A liquid level detection device, characterized in that the photoelectric switch is arranged so that the light at the upper end of the high-intensity portion of the optical trajectory created by the lens action of the liquid in the container is received by the photoelectric switch.