JPS5822096Y2 - Liquid level detection device - Google Patents

Description

[Detailed explanation of the invention] In this invention, a float is attached to the other end of the shaft frame which is rotatably supported as one end of the rotational fulcrum, and the float is floated on the liquid surface to detect the liquid level height and eventually the liquid volume. In the device,
It has a means for converting the vertical movement accompanied by arcuate movement of the float into a linear vertical movement, and the linear vertical movement is supplemented by a rotation that is in a non-linear relationship between the rotation angle of the float support frame and the liquid level height displacement or liquid volume displacement. Then, the rotation shaft is rotated with a rotation angle that is linearly proportional to the liquid level height displacement or liquid volume height displacement, and this rotation angle is detected. This invention relates to a liquid level height or liquid amount detecting device that uses 5vc so as not to follow temporary fluctuations due to fluctuations or acceleration.

Conventionally, in this type of detection device, as described above, a slider contact of a variable resistor generally used as rotation angle detection means is simply attached to the rotation fulcrum of the float support frame.

Therefore, since the rotational angular displacement of the arcuate motion that occurs when the float moves up and down following the liquid level height displacement is not linearly proportional to the liquid volume due to irregularities in the shape of the tank containing the device, it is natural that the slider contact The sliding rotation angle on the stator winding also becomes non-linear.

Therefore, the resistance change between one end of the stator winding and the slider contact can be reduced by simply winding the stator winding at a uniform pitch or the same length per turn. On the other hand, it becomes non-linear, and the display scale of the display meter driven by the converted current change due to the resistance value change cannot also be a uniform scale.

Conventionally, to compensate for this, the pitch of the stator winding was changed for each part, or the shape of the resistor winding winding plate was changed from a rectangular shape to change the length of the winding for each part. Of course, I was making up for it.

How to change the pitch and how to geometrically determine the special shape of the winding plate in order to change the length of each winding for each part is very complicated in terms of design, and Manufacturing became complicated and troublesome, and manufacturing tolerances also became very large, resulting in poor product yields.

Furthermore, conventional devices are too sensitive to fluctuations in liquid level;
Therefore, when used as a fuel gauge in a vehicle, small fluctuations in the liquid level due to external vibrations etc. are detected as they are, making the 1-display meter extremely difficult to see. The liquid level may be incorrectly displayed by following the slope of the liquid level.

In view of the above, the present invention has been developed so that the rotation angle detection means such as a variable resistor, which is difficult to manufacture, is designed to detect the rotation angle linearly proportional to one rotation angle. This allows the winding to be uniform and the length of the winding per turn to be uniform, and the non-linearity between the float arc motion rotation angle and the liquid volume due to the liquid level height displacement can be easily designed. The main purpose of this design is to compensate for this with another mechanical part, and to create a structure that does not follow extremely minute fluctuations or displacements in the liquid level within a short period of time.

Note that the liquid level height detection device and the liquid amount detection device are essentially the same concept, and the difference is only in terms of descriptive expression (if the liquid level height can be detected, it is possible to detect the shape or contents of the tank containing the liquid). In this specification, the expression ``liquid surface height detection device'' is chosen from among the liquid landscape display on the display according to the change in the height direction of the liquid.

The illustrated embodiment will be described in detail below.

On the top plate 1 of the tank that stores the liquid F whose liquid level height or liquid volume is to be measured, the partial height detection device 2 of this embodiment is mounted using its support frame (or lid) 3 (polishing material) 4a + packing material, etc. It is suspended via fixing means such as a seal 4b.

A fulcrum support member 7 hangs down from the support frame 3 and has a float part fulcrum structure 6 that pivotally supports the other end of the support frame 5 which supports the float 4 at one end thereof as a rotational fulcrum P.

In this case, the fulcrum support member 7 extends further downward and supports a bearing structure 8 having a lower bearing structure 8a at its free end side.

The lower bearing 8a and, in this case, the upper bearing 8b provided on the back surface of the support frame 3 are located at positions linearly opposed to each other, and a rotating means is provided which is supported at both ends (pivot bearings in the illustrated case) across both bearings. 9 is rotatably housed.

In this embodiment, the rotation means or rotation shaft 9 is arranged at a position where it intersects the float support frame 5 when projected on a plane as on the surface of one drawing, that is, at a spatially twisted position. .

Near the support frame side bearing 8b of the rotating shaft 9, as described later,
The slider contact 10a of the variable resistor 10, which is a general example of the rotation angle detection means of the shaft, and furthermore, the liquid level height detection means, is fixed and its actual sliding end, which rotates with the rotation shaft, is connected to the support frame. The stator winding 10b is arranged circumferentially at a predetermined angle along the inner wall of the case 3a provided in the case 3, and slides on the exposed surface, in this case, the upper end surface.

A cylindrical sleeve 11 is loosely fitted around the outer periphery of the rotating shaft 9. The sleeve extends downward from the case 3a, and axially swings on the rotating shaft within a cylindrical portion 3b that also serves as vertical guide means for the sleeve. It is arranged so that it can move freely up and down.

Although not shown in the drawings, at least one key groove is bored in the axial direction in the cylindrical part, and the number of key grooves corresponding to the key grooves provided in the length direction (axial direction) on the outer periphery of the cylindrical sleeve 11 is small. A single key line 11a is fitted in each case, thereby preventing rotation of the cylindrical sleeve 11.

In other words, the cylindrical portion 3b provided in the support frame (in this case indirectly via the case 3a) is connected to the sleeve 11.
It can be said to be a means of preventing rotation by only allowing vertical movement.

A portion of the outer circumferential surface of the sleeve 11, in this case the lower end portion, which serves as a linear vertical movement means whose movement is restricted only in the vertical direction, has a pair of spaced apart pins 12a that protrude perpendicularly to the axial direction. 12b are planted, and the float support frame 5 is inserted between these pickets.

Therefore, when the float 4 descends, the lower pin 12a engages in point contact with the float support frame 5, which is also descending, and is pushed downward, thereby causing the sleeve to move downward.
Conversely, when the float rises, the upper pin 12b is pushed up by the float support frame 5, and the sleeve also moves upward.

In the case shown in the figure, when the liquid is full or close to it, the float has a 9-point cut at the top, and the support frame 5 has both pins 12a and 1.
2b, and cannot move upward any further.

At this time, most of the sleeve 11 has also entered into the cylindrical portion 3b.

On the other hand, as shown by the imaginary line, there is a position 1 where the float has completely lowered and there is no need to detect a decrease in the liquid level. When the sleeve 11 reaches a position where there is a margin for fluid consumption (many fuel gauges in vehicles are like this), the sleeve 11 is generally removed from the rotation prevention means or the cylindrical portion 3b. However, even at that time, it is necessary to maintain the engagement between the rotation prevention means 3b and the sleeve 11 so that rotation is prevented before rising again, and in the case of the mechanism shown in the figure, the key as the rotation prevention means The length of the cylindrical portion 3b is such that it can engage at least the upper end of the sleeve even at its lowest position.

In this way, the outer peripheral wall of the sleeve 11, which only moves up and down, has a torsion curve determined arbitrarily as described below.
A torsion groove 11b is cut at a predetermined angle in the circumferential direction, and within this groove is a rotation-generating engagement that protrudes from the outer peripheral surface of the one-rotation shaft 9 and substantially makes point contact with a part of the wall surface of the groove. The rod 13 as a means is included.

Therefore, as described above, when the float 4 moves up and down following the liquid level and the sleeve (linear up and down movement means) 11 moves up and down, the sleeve is prevented from rotating, while the rotating shaft 9
Since the protruding frame 13 cannot move in the vertical direction, the protruding frame 13 applies a force in the circumferential direction of the rotating shaft 1 following the torsional locus of the torsion groove 11b cut in the sleeve.

As a result, the rotating shaft 9 is rotated by the torsion groove 11b of the sleeve 11.
The shaft rotates with a rotation angle displacement corresponding to the torsion curve of the shaft, and the rotation angle detection means 10 of the shaft detects the rotation angle (in this case, the variable resistor 100 is a slider fixed to the rotation shaft). The contact 10a assumes a position according to the rotation angle and produces a resistance value commensurate with the rotation angle between it and one end of the stator winding; 10C210d is located at the slider contact and one end of the stator winding, respectively. This is a terminal for communicating with an electrically connected external device).

Therefore, when detecting the liquid level, the float moves up and down in an arcuate manner non-linearly in response to the displacement of the liquid level.

Therefore, in the case where the linear vertical movement of the sleeve 11 is non-linear with the liquid volume displacement, in order to make the rotation angle of the rotating shaft 90 linearly proportional to the liquid volume, it is necessary to adjust the torsion curve or pitch of the torsion groove of the sleeve 11. may be determined to compensate for the above non-linear relationship, and this curve can be easily determined in terms of design.

When a variable resistor is conventionally used as the rotation angle detection means for the rotating shaft 90, in order to obtain the resistance value change linearly according to the liquid volume displacement, as described above, the so-called mechanical If the rotation angle of the rotating shaft is made linearly proportional to the liquid volume displacement by physical means, the production of stator windings does not require complicated processes and can be easily done with uniform pitch and length each time. This means that there is no variation from device to device, and reliability is increased.

Of course, if desired, specific functional relationships other than linear proportionality can easily be achieved with mechanical configurations such as those described above.

In addition, the float buoyancy is clearly converted into rotational torque of the rotating shaft through the support birch using the lever principle, so it is necessary even if the rotating shaft has a small diameter or the float is small. It is possible to obtain a large amount of torque, and it does not take up a large capacity in the tank.

The present applicant uses a multi-line optical transmission path to detect the angle of one rotation or the amount of deposited liquid in the liquid surface height direction, instead of using an analog device such as a variable resistor as described above. A digital method is separately disclosed that selectively opens and closes an optical transmission line corresponding to each scheduled position depending on the presence or absence of liquid at the scheduled position.

By selectively intervening a shielding plate that rotates around one point in the gap between the light source and each light receiving and transmitting path on the display side, the light source and each light receiving and transmitting path are There are devices that control circuit closure, but these devices can be applied to the device of the present invention, and it is sufficient to fix them, for example, above the rotating shaft so that the center of rotation of the shielding plate is the rotating shaft 9. , the light source and each light receiving transmission path are connected to the rotational movement of the shielding plate (
It can be used as a digital rotation angle detection means 10 if it is placed within the range of ) in a plane perpendicular to the axis with a gap equal to the shielding root in the vertical direction.

In the illustrated case, the means for causing the rotation shaft 9 to rotate is composed of a linear vertical movement means or a torsion groove bored in the sleeve 11 and an engagement frame 13 fitted into the groove, but this relationship can be reversed. In other words, a predetermined angle in the circumferential direction (
A groove may be bored along the lengthwise direction by an angle (angle required to drive the rotation angle detection means) along a twisted curve, and a protruding frame may be provided on the inner wall surface of the sleeve to fit into the groove. Also.

Instead of fitting the sleeve onto the rotating shaft so that it can freely slide, the two may be arranged in parallel so that the above-mentioned torsion curve and the rod engage with each other at their contact surfaces or adjoining surfaces. .

As another modification, the float support rod 5 may be further extended from the fulcrum P, and the detector may be placed on the right side of the fulcrum P (opposite the float) in the drawing so that the sleeve engages with that part. In that case, it goes without saying that the rotation of the rotary shaft relative to the vertical movement of the sleeve will be opposite to that shown in the drawings.

Further, in the illustrated embodiment, from practical considerations, the movement of the float 4 is damped to a certain extent when the liquid level fluctuates or when the liquid has an acceleration equal force cut, so as not to unnecessarily follow the liquid level fluctuations. A braking means 14 is provided to avoid erroneous detection as much as possible.

In this case, it is fixed near the lower bearing 8a of the one-rotation shaft 9,
A vane means rotating together with the rotating shaft serves as this braking means.

In other words, even if the liquid level fluctuates due to some unforeseen factor and the float is about to follow it, the resistance of the liquid will cause it to oscillate.
The blades 14 are small enough to apply a brake to the rotary shaft 9, and are also small enough to brake the vertical movement of the float.

Therefore, the float is kept at approximately the same position as when the liquid level is level.
The rotating shaft does not undergo rotational oscillation, and the detection means does not cause noise in the measurement system or causes of erroneous detection, such as resistance pulsation.

Similarly, in the case shown, one blade is in a spiral shape,
If the direction of this spiral is opposite to the twisting direction of the groove means of the sleeve, the braking capacity will be further increased.

The cylindrical wall means 15 provided so as to surround the braking means also includes:
By limiting the amount of liquid facing the braking means to a certain amount, even if the vibration becomes quite large in the external liquid, the liquid surrounding the braking means is kept as calm as possible by the resistance of its own walls, and is relatively The purpose is to increase the resistance of the blades to the swinging liquid and improve the braking function.

Further, one end of a rod-shaped member 16 that extends to the vicinity of the tank bottom (not shown) is fixed to the lower bearing structure 8.

At its tip, a warning light lighting circuit closing means 17 is provided when there is no or very little remaining oil.

This is a particularly convenient device as a vehicle fuel gauge.

The structure is simple, with one fixed contact 18a (in this case, a pair)
On the other hand, only the movable contacts 18b (in the case shown, a pair) attached to the float 19, which rotates vertically about the fulcrum Q'Y depending on whether or not it receives buoyancy depending on the presence or absence of liquid, are facing.

When the amount of liquid is exhausted and the float is released from buoyancy, it lowers due to its own weight and contacts the fixed contact 18a (flow) 11jl contact 18b, thereby closing a warning light (not shown) lighting circuit.

Note that the one-circuit cord 20 may be appropriately extended upward and led out from the detection body.

Regardless of such ancillary devices, when the liquid level detection device of the present invention is applied as a liquid level meter, etc., the liquid level displacement and the detected amount (rotational angular displacement) can be linearly proportional or in a desired functional relationship. It is easy to manufacture and can be adopted with a one-sided mechanical structure, and the rotation angle detection means, which is difficult to manufacture in the first place, is not unnecessarily complicated, and the reliability of the device as a whole is improved. In addition, due to the lever relationship between the float support rod and the sleeve as a linear vertical movement means, sufficient rotational force can be obtained even if the float buoyancy and the size of the float are small, and the rotation shaft is also small in diameter. This ultimately contributes to miniaturization, and since it does not follow extremely minute fluctuations or temporary inclinations of the liquid level, it has the effect of eliminating difficult-to-read displays and erroneous displays.

[Brief explanation of the drawing]

The drawing is a sectional side view of a main part of an embodiment of the liquid level detection device of the present invention. In the figure, 2 is the overall liquid level height detection device, 4 is a float, 5 is its support frame, and 8a and 8b are bearings. 9 is a rotating means, 10 is a variable resistor means as an example of rotation angle detecting means (liquid level height detecting means), 11 is a linear vertical movement means or sleeve, 11a is a key string for preventing rotation, 11b
12a is a torsion groove for rotating the rotating shaft. 12b is a float support engagement means, and 13 is an engagement frame for engaging the groove 11b.

Claims (1)

[Claims for Utility Model Registration] A float support frame having a float means that follows the liquid level at one end and moves in an arc by the movement of the float means that follows the liquid level using a point on the other end as a rotational fulcrum. a sleeve that is in a twisted position with the float support frame and is prevented from rotational movement but allowed to move up and down in a straight line; a pair of pins that linearly move the sleeve up and down in accordance with the arcuate movement following the liquid level of the float; A rotating shaft that is fitted concentrically into the sleeve and is rotatably supported around the vertical axis of the sleeve. and rotation angle detection means for detecting a rotation angle of the rotation shaft. A protruding rod provided on one of the sleeve and the rotating shaft in a direction perpendicular to the axis; and a pair of rotation generating means for rotating the rotating shaft as the sleeve moves up and down in a straight line. a vane means provided on the rotating shaft, receiving a resistance force due to the viscosity of the liquid, and applying a brake to the float swinging due to the temporary swinging of the liquid level; A liquid level detection device comprising: