KR20000038465A - Apparatus for measuring liquid level - Google Patents

Abstract

PURPOSE: A liquid level measurement apparatus is provided to enhance the reliability through the minimization of the movement range of a float by restraining the movement direction of the float in a vertical direction. CONSTITUTION: A supporter(25) has a through hole(25a). A guide member(30) is slidably inserted into the through hole(25a). A float(40) is connected to a lower portion of the guide member(30). A position sensor(50) measures a liquid level. the supporter(25) is provided on the upper portion of the inner side of a container(20). the through hole(25a) is formed in the vertical direction with respect to the supporter(25), that is, in a level variation direction of remaining liquid. The movement of the supporter(30) is restrained in the vertical direction by the through hole(25a).

Description

Liquid level measuring device

The present invention relates to a liquid level measuring device for measuring the level of the liquid contained in the container to detect the remaining amount of liquid in the container.

In general, a wet developing printer such as a laser printer or a copier, which uses ink as a developer, employs an apparatus for measuring the level of liquid contained in a container so as to detect the remaining amount of ink and replenish the ink at an appropriate time.

As shown in FIG. 1, a conventional liquid level measuring device includes a lever 10 having a first angle and a second arm 11 and 12 formed at a predetermined angle so as to be rotatable about a hinge axis 18. The floating body 19 attached to the end of the first arm 11 located in the container 13 and the rotation path of the second arm 12 are installed to allow passage of the second arm 12. It consists of a plurality of sensing sensors 14 for sensing. Here, the sensor 14 is discontinuously arranged to detect the lower limit, the titration line, the upper limit of the remaining amount of liquid, as shown.

The first arm 11 is pivoted about the hinge axis 18 in conjunction with the floating body 19, which is buoyant according to the level of the liquid in the container 13, and the second arm pivoted in conjunction with it. The vertical position change of 12 is detected at the sensor 14.

As described above, the vertical position of the floating body 19 is changed according to the level change according to the remaining amount of liquid in the container 13, and the vertical position change of the second arm 12 linked thereto is detected by the sensor 14. The level of the liquid was measured.

However, such a liquid level measuring device has a disadvantage in that a large number of detection sensors 14 are installed along the rotation path of the lever 10, so that the occupied space becomes large. In addition, since the floating body 19 has a large range of motion, when a liquid level measuring device having such a structure is employed in a wet printer or the like, a malfunction may occur such that the floating body 19 rubs against the wall surface of the ink container. In addition, it is difficult to properly cope with the error of the printing operation due to the exhaustion of ink that may occur during the printing operation by accurately detecting the remaining ink level and replenishing the ink at the appropriate time.

The present invention has been made in view of the above, and an object thereof is to provide a liquid level measuring device having improved reliability by minimizing the range of motion of a floating body.

1 is a view schematically showing a conventional liquid level measuring device,

2 is a partial cutaway perspective view schematically showing a liquid level measuring device according to the present invention;

3 is a cross-sectional view taken along line III-III of FIG. 2;

4 is a graph schematically showing a liquid remaining amount detection signal of a liquid level measuring device according to the present invention.

<Description of the code | symbol about the principal part of drawing>

20 Container 25 Support member

25a ... through hole 30 ... guide member

40 ... Fluid 50 ... Position sensor

51 ... Positioning member 51a ... Light pass

53 ... light source 55 ... photodetector

57 ... Spring

Liquid level measuring apparatus according to the present invention for achieving the above object is provided above the inside of the container and the support member is formed in the through hole in the vertical direction; A guide member slidably fitted into the through hole; A floating body floated by buoyancy of the liquid contained in the container and coupled to the lower end of the guide member, the floating direction of which is restricted by sliding of the guide member along the through hole; And a position sensor that detects a change in position of the floating body according to the level of the liquid contained in the container and measures the level of the liquid.

The position sensor may include: a position display member coupled to the guide member and having a light passing portion provided to continuously increase the light passing amount according to the position; A light source disposed at one side of the position display member to irradiate light to the light passing portion; And a photodetector disposed to face the light source and receiving the light passing through the light passing portion.

On the other hand, between the guide member and the floating body is preferably further provided with an elastic spring to limit the moving range of the floating body.

Such a liquid level measuring device measures the level of the liquid contained in the container by measuring the change in the amount of light passing through the change in the position of the floating body.

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

2 is a perspective view schematically showing a liquid level measuring apparatus according to an embodiment of the present invention, Figure 3 is a cross-sectional view taken along the line III-III of FIG.

2 and 3, the liquid level measuring apparatus according to the present invention includes a support member 25 having a through hole 25a and a guide member 30 slidably fitted into the through hole 25a. , A floating body 40 coupled to the lower end of the guide member 30, and a position sensor 50 for measuring the level of the liquid.

The support member 25 is provided above the inside of the container 20, and the through hole 25a is formed in a direction perpendicular to the support member 25, that is, in a direction of changing the remaining amount level of the liquid. Therefore, the guide member 30 slidably fitted into the through hole 25a is guided by the through hole 25a so that its movement is limited in the vertical direction.

The float 40 is floated by the buoyancy of the liquid contained in the vessel 20. When the remaining amount of liquid contained in the container 20 is high buoyancy is increased and the floating body 40 is moved upwards, when the remaining amount of liquid is small buoyancy is reduced and the floating body 40 is moved to the lower side. That is, the vertical position of the float 40 changes according to the remaining level of the liquid contained in the vessel 20.

In this embodiment, the float 40 is coupled to the lower end of the guide member 30. Therefore, the floating body 40 is limited in the direction of movement by the guide member 30 sliding along the through hole (25a).

On the other hand, it is preferable that the partition member 27 extends downward from the support member 25 to the inner side of the container so that the movement in the horizontal direction of the floating body 40 is limited within a predetermined range.

The position sensor 50 measures the level of the liquid by detecting a change in the position of the floating body 40 whose position is changed by receiving buoyancy according to the remaining liquid level contained in the container 20. To this end, the position sensor 50 includes a position display member 51 and an optical sensor 52.

The position display member 51 is coupled to one side of the guide member 30, for example, the upper side of the guide member 30 that has passed through the through hole 25a, and has a light passage provided to continuously increase the light passing amount according to the position. The part 51a is provided. Here, the light passing portion 51a may be provided to continuously increase the light passing amount according to its position from above to below, or from below to above. FIG. 2 shows an example in which the light passing portion 51a is formed of a hole 51a having a triangular shape, for example, an isosceles triangle, so that the light passing area is increased from below. On the other hand, the light passing portion 51a may be provided as a member for varying the light transmittance according to the position.

The optical sensor 52 includes a light source 53 and a photodetector 55. The light source 53 is disposed on one side of the position display member 51 to irradiate light to the light passing portion 51a. The photodetector 55 is disposed to face the light source 53 to receive the light passing through the light passing part 51a.

On the other hand, the guide member 30 is preferably provided with a plate 56 between the support member 25 and the floating body 40. The lower end of the plate 56 and the position display member 51 limits the vertical movement range of the float (40).

On the other hand, it is preferable to further include an elastic spring 57 between the support member 25 and the floating body 40, preferably between the support member 25 and the plate 56 provided on the guide member 30. Do. The elastic spring 57 is fitted to the guide member 30 and supports the movement of the floating body 40 stably by buoyancy of the liquid by its elastic force, and supports the vertical movement range of the floating body 40. Restrict.

In the absence of the elastic spring 57, the maximum moving range of the floating body 40, that is, the moving range of the floating body 40 when the liquid level change is changed from the lower limit level to the upper limit level or vice versa, is, for example, In the case of water, it is approximately equal to the height between the upper and lower limit levels. Of course, a liquid having a viscosity such as ink has a smaller moving range than that of water.

However, as described above, when the elastic spring 57 is provided, the vertical movement range of the floating body 40 is relatively reduced by the elastic bias force of the elastic spring 57 than when the elastic spring 57 is not provided. Therefore, the installation space of the liquid level measuring device can be reduced.

The liquid level measuring device as described above operates as follows.

When the remaining amount level of the liquid contained in the container 20 is located at the lower limit line L, the photodetector 55 detects the light emitted from the light source 53 and passed through the light passing portion 51a to FIG. 4. As shown, a low signal is generated.

When the liquid is replenished in the container 20, the remaining liquid level is increased, and the floating body 40 is moved upward by the buoyancy, whereby the position display member 51 is moved upward. Therefore, the amount of light passing through the light passing portion 51a increases linearly in response to the position rise of the floating body 40, and the photodetector 55 increases the detection signal linearly in proportion to the liquid remaining level. Generates a signal corresponding to

When the liquid in the container 20 is filled up to the upper limit H, that is, the rising range of the floating body 40 or the detection range of the position sensor 50 (limited by the light passing portion 51a), the photodetector ( 55 generates a high signal.

On the other hand, when the remaining amount of the liquid contained in the container 20 is reduced, the liquid level measuring device operates in the reverse of the above.

The liquid level measuring apparatus according to the present invention as described above can continuously measure the level change of the liquid remaining in the container. In addition, since the moving direction of the floating body is limited to the vertical direction, and the moving range of the floating body with respect to the level change of the liquid is reduced by the elastic biasing force of the elastic spring, the space occupied by the liquid level measuring device is minimized. It can be implemented, and no malfunction occurs.

Therefore, when employed in a wet printer, it is possible to accurately detect the remaining amount of the ink contained in the ink bottle so that ink can be replenished at an appropriate time.

Claims (3)

A support member provided above the inside of the container and having a through hole formed in a vertical direction; A guide member slidably fitted into the through hole; A floating body floated by buoyancy of the liquid contained in the container and coupled to the lower end of the guide member, the floating direction of which is restricted by sliding of the guide member along the through hole; And a position sensor for detecting a change in the position of the floating body according to the level of the liquid contained in the container and measuring the level of the liquid. The method of claim 1, The position sensor, A position indicating member coupled to the guide member and having a light passing portion provided to increase the light passing amount according to the position; A light source disposed at one side of the position display member to irradiate light to the light passing portion; And a photodetector disposed to face the light source to receive the light passing through the light passing portion, and measuring a level of the liquid contained in the container by measuring a change in the amount of light passed according to a change in position of the floating body. Liquid level measuring device. The liquid level measuring device according to claim 1 or 2, further comprising an elastic spring for restricting a moving range of the floating body between the guide member and the floating body.