JPH0783732A - Device for detecting quantity of liquid in container - Google Patents

Abstract

PURPOSE:To simplify the liquid quantity detecting constitution of a device for detecting quantities of liquids in containers and to enable the device surely detect the quantity of a liquid irrespective of the material of the containers, the kind of the liquid, etc., and also, prevnet the fluctuation in liquid quantity detection results. CONSTITUTION:A weight member 2 is mounted on a prescribed side edge side of a container and fulcrum member 3 is provided at a prescribed position on the member 2 mounting position side of the center of gravity of the container 1. In addition, a limit switch 5 which is operated by means of a prescribed position of the container 1 when the container 1 is rotated in one direction around the member 3 is also provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting the amount of liquid in a container, and more particularly to a device for detecting whether or not the amount of liquid in the container is a predetermined amount or more.

[0002]

2. Description of the Related Art Conventionally, a device using a float, a device using an optical detector, and a device using an electrode are known as devices for detecting whether or not a liquid amount in a container is a predetermined amount or more. ing. Among these, the device using the float has a float inside the container,
A detection mechanism for detecting the position of the float that moves up and down following the liquid level in the container is provided, and it is possible to detect whether or not the liquid amount is a predetermined amount or more by the detection mechanism.

An apparatus using an optical detector has a light emitter and a light receiver arranged at predetermined positions facing each other with a container made of a transparent material interposed therebetween, and the container is placed between the light emitter and the light receiver. The state where only the side wall of the container exists (the state where the liquid amount is small) and the state where the side wall of the container and the liquid exist (the state where the liquid amount is large) can be detected based on the difference in the received light amount. it can.

A device using electrodes comprises a pair of electrodes arranged close to each other at a predetermined position inside the container, and the state that the liquid level is below the tip of the electrode and information is The state of being positioned can be detected based on the magnitude of the electric resistance value between both electrodes.

[0005]

When a device using a float is adopted, not only the structure for detecting the position of the float becomes complicated but also the liquid amount detection accuracy becomes low. is there. Further, since it is necessary to store the float in the container at all times and keep it in contact with the liquid, there is a disadvantage that the degree of freedom in selecting the float material is reduced. In particular, when the liquid is a reagent for measurement, it is necessary to select a material that has no risk of degrading the reagent, and the degree of freedom in selecting the material is significantly reduced. Further, if the liquid level in the container changes due to vibration or the like, the liquid amount detection result is greatly affected by the liquid level change.

When an apparatus using an optical detector is adopted, it is necessary to increase the transparency of the container itself as much as possible. However, if dirt is attached to the outer surface of the container due to long-term use, it becomes dirty. May cause the liquid amount to be erroneously detected. In particular, when the container contains waste liquid, the waste liquid adheres to the wall surface of the container, resulting in erroneous detection of the amount of waste liquid. Further, since the liquid amount is detected based on the difference in the amount of received light between the case where the liquid is present and the case where the liquid is not present between the light projector and the light receiver, for example, it is necessary to detect the amount of the liquid having extremely high transparency. Becomes almost impossible. Of course, when the transparency of the container is not so high, it becomes almost impossible to detect the amount of the liquid even if the transparency of the liquid is not so high. Further, if the liquid level in the container changes due to vibration or the like, the liquid amount detection result is greatly affected by the liquid level change.

When an apparatus using electrodes is adopted, the distance between the electrodes is set to be small, so that even if the amount of liquid is reduced, liquid droplets may remain between the electrodes. This is extremely high, and as a result, the possibility of erroneously detecting whether or not the amount of liquid is equal to or greater than a predetermined amount is considerably increased. In addition, not only liquid drops but also stains are likely to cause erroneous detection. Further, since the pair of electrodes is immersed in the liquid when the amount of the liquid is large, the degree of freedom in selecting the electrode material is reduced as in the case of using the float. Furthermore, if the liquid level in the container changes due to vibration or the like, the liquid amount detection result may vibrate. Since the electrode is often attached integrally to the liquid dispensing nozzle, the dispensing nozzle must be washed after the liquid amount is detected.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems and is capable of detecting the amount of a liquid without contacting the liquid, and regardless of the stain, material, etc. of the container for containing the liquid. An object of the present invention is to provide a liquid amount detection device in a container, which can accurately detect the amount of liquid and can prevent the vibration of the liquid amount detection result.

[0009]

In order to achieve the above object, a liquid amount detecting device in a container according to claim 1 has a container having an eccentric center of gravity on the side end side, and a predetermined amount of the container. A fulcrum member arranged at a position corresponding to a predetermined position on the lower surface of the container that faces the center of gravity of the entire liquid in a stored state, and a state in which the amount of the liquid stored in the container is larger than the predetermined amount or And container detecting means which is operated based on a predetermined position of the container in a state of less than a predetermined amount.

Here, the container having a center of gravity position eccentric to the side end may be one in which a weight is attached at a predetermined position, but a predetermined side wall and a predetermined range of the bottom plate adjacent to the predetermined side wall. May be formed in a thick shape,
Also, an auxiliary plate member for eccentricizing the center of gravity may be integrally provided. Further, the fulcrum member may be provided on the upper surface of the support base that supports the container, or may be provided on the lower surface of the container. Further, the container detection means may be mechanical detection means typified by a limit switch, or may be optical detection means typified by a photosensor,
Further, it may be magnetic detection means represented by a proximity switch.

In the liquid amount detecting device in the container of the second aspect, as the fulcrum member, one having the lower surface of the container as a fulcrum is adopted.

[0012]

According to the liquid amount detecting device in the container of claim 1,
A fulcrum member is arranged at a position corresponding to a predetermined position on the lower surface of the container that faces the overall center of gravity in a state where a predetermined amount of liquid is contained in the container having a center of gravity eccentric to the side end portion, and is stored in the container In a state in which the amount of the applied liquid is larger than the predetermined amount or smaller than the predetermined amount, the container detection means is operated based on the position of the container operating with the fulcrum member as the fulcrum. Therefore, it is possible to accurately detect whether or not the amount of liquid in the container is equal to or larger than a predetermined amount, based on whether or not the container detection means is operated. Of course, since neither the fulcrum member nor the container detecting means comes into contact with the liquid, it is possible to prevent alteration of the liquid even when the liquid is a reagent for measurement. Further, rather than detecting the liquid level, the predetermined position of the container that operates with the fulcrum member as the fulcrum is detected, so that the amount of liquid in the container can be determined without being affected by the material and dirt of the container. It is possible to accurately detect whether or not the amount is equal to or more than the fixed amount. Further, when the container once moves to one side with the fulcrum member as the fulcrum, the liquid flows to promote this operation, so that the vibration of the liquid amount detection result can be prevented in advance. That is, it is possible to make the liquid level almost unaffected. Furthermore, when the float is used, the configuration can be simplified as compared with the case where the electrode is used.

According to the liquid amount detecting device in the container of the second aspect, in addition to the action of the first aspect, the response to the change of the position of the center of gravity due to the change of the liquid amount can be made good.

[0014]

Embodiments will be described in detail below with reference to the accompanying drawings showing embodiments. FIG. 1 is a schematic view showing an embodiment of a liquid amount detecting device in a container according to the present invention.
The weight member 2 is attached to the upper part of the predetermined side end portion, and the lower surface predetermined position of the container 1 corresponding to the center of gravity position in a state where a predetermined amount of liquid is stored in the container 1 is defined by the fulcrum member 3. It is supported. Further, a supporting member 4 for holding the container 1 in a substantially horizontal state by engaging with a predetermined position on the lower surface of the container 1 on the side where the weight member 2 is mounted is provided, and the container 1 held in a substantially horizontal state. There is provided a limit switch 5 which is operated at a predetermined upper position on the side opposite to the side where the weight member 2 is mounted. In addition, 6 is a support stand.

The operation of the liquid amount detecting device having the above structure is as follows. When no liquid is contained in the container 1, a force in the direction in which the weight member 2 mounting side rotates downward about the fulcrum member 3 acts on the container 1, so that the container 1 is supported by the fulcrum member 3. And it is held in a substantially horizontal state by the support member 4. Therefore, limit switch 5
Is operated at the above predetermined position of the container 1, and it can be detected that the amount of liquid in the container 1 is less than or equal to a predetermined amount. The posture of the container 1 does not change until the amount of the liquid stored in the container 1 reaches the predetermined amount.
When the amount of the liquid contained in the container 1 exceeds the above-mentioned predetermined amount, the position of the center of gravity in the state where the container 1 and the liquid are integrated moves to the center side of the container 1 rather than the fulcrum member 3. The force opposite to the above acts on 1 and the container 1 rotates so that the weight member 2 mounting side rises (see the broken line in FIG. 1). In this case, if the container 1 rotates even a little, the liquid flows into one side of the container 1 so as to promote the rotation, so that the container 1 can be operated even in the boundary state where the amount of the solution slightly exceeds the predetermined amount. It will not be held in an unstable state and will rotate to the rotation limit position and be stable. Then, since the limit switch 5 is brought into a non-operating state with the rotation of the container 1, it is possible to detect that the liquid amount exceeds a predetermined amount by a not-shown discriminating unit.

As is clear from the above, the center of gravity position is changed according to the amount of liquid, and the center of gravity position is changed to a predetermined position, whereby the container 1 is rotated about the fulcrum member 3. The structure is simple, and it is possible to reliably detect whether or not the amount of liquid is less than or equal to a predetermined amount. Of course, the detection of the liquid amount can be achieved regardless of the material of the container 1 and the type of liquid. Also, the fulcrum member 3
However, since the lower surface of the container 1 is used as the fulcrum, the response can be improved.

Although only the case where the amount of the liquid in the container 1 increases has been described above, the same can be applied to the case where the amount of the liquid decreases. However, in this case, the position of the center of gravity as a whole is slightly shifted toward the center of the container 1 due to the liquid being initially biased. Therefore, when the liquid is reduced to a predetermined amount smaller than the above-mentioned predetermined amount, the container 1 rotates to operate the limit switch 5.

Further, instead of the limit switch 5, it is possible to employ a photo sensor for detecting a predetermined position (for example, a predetermined position of the upper end portion) of the container 1.

[0019]

[Embodiment 2] FIG. 2 is a schematic view showing another embodiment of the liquid amount detecting apparatus of the present invention. The difference from the embodiment of FIG.
The weight member 2 is omitted, and the container 1 on the side where the weight member 2 is mounted
The only difference is that the side plate is thick and also serves as a weight member. Therefore, in the case of this embodiment, the work of mounting the weight member 2 is unnecessary, and the same operation as that of the liquid amount detecting device of FIG. 1 can be achieved.

The present invention is not limited to the above-described embodiment. For example, the fulcrum member 3 can be mounted on the lower surface of the container 1, and the weight member 2 made of metal can be used.
It is possible to employ a proximity switch arranged in a position close to the weight member 2 in place of the limit switch 5 in addition to employing A photo sensor can be used instead of the switch 5, and various design changes can be made within a range that does not change the gist of the present invention.

[0021]

As described above, the invention of claim 1 accurately detects whether or not the amount of liquid in the container is equal to or more than a predetermined amount, based on whether or not the container detecting means is operated. Moreover, since neither the fulcrum member nor the container detection means comes into contact with the liquid, it is possible to prevent alteration of the liquid even when the liquid is a reagent for measurement, and to detect the liquid level. Rather than detecting the predetermined position of the container that operates with the fulcrum member as a fulcrum, the material of the container,
It is possible to accurately detect whether the amount of liquid in the container is a predetermined amount or more without being affected by dirt and the like, and when the container once moves to one side with the fulcrum member as a fulcrum. In addition, since the liquid flows so as to promote this operation, there is a peculiar effect that the vibration of the liquid amount detection result can be prevented in advance.

In addition to the effect of claim 1, the invention of claim 2 has a peculiar effect that the response to the change of the center of gravity position due to the change of the liquid amount can be improved.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a liquid amount detecting device in a container according to the present invention.

FIG. 2 is a schematic view showing another embodiment of the liquid amount detecting device in a container according to the present invention.

[Explanation of symbols]

 1 container 3 fulcrum member 5 limit switch

Claims (2)

[Claims] 1. A container (1) having an eccentric center of gravity on the side end side, and a predetermined position on the lower surface of the container facing the overall center of gravity when a predetermined amount of liquid is contained in the container (1). The fulcrum member (3) arranged at a corresponding position and the position of the container (1) in a state where the amount of the liquid contained in the container (1) is larger than the predetermined amount or smaller than the predetermined amount. An apparatus for detecting a liquid amount in a container, comprising: a container detecting means (5) which is operated based on the above. 2. The liquid amount detecting device in a container according to claim 1, wherein the fulcrum member (3) uses the lower surface of the container as a fulcrum.