JPH07324962A - Liquid level sensor mounting device - Google Patents

Abstract

(57) [Abstract] [Purpose] In the conventional mounting device for the liquid level sensor, the liquid level is caused by all factors such as the mounting state to the liquid tank, the inclination of the liquid tank itself, and the inclination when the device having the liquid tank is installed. There is a problem that the positional relationship between the liquid level sensor and the liquid level sensor is out of order and the accuracy is lowered. According to the present invention, the attachment device 1 is provided with a weight 4 and a universal joint 5, and the universal joint 5 is provided between the attachment fitting portion 3 and the holder portion 2 and the holder portion 2 is provided by the gravity of the weight 4. Since the mounting device 1 is configured to displace the liquid surface sensor 10 held in the predetermined direction with respect to the liquid surface, the predetermined value automatically indicates the mutual relationship between the liquid surface sensor 10 and the liquid surface due to gravity. As a matter to be set, the problem is solved by automatically setting to a prescribed value in any state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a liquid level sensor provided in a liquid tank for warning, for example, a shortage of fuel in a combustion type heater or water in a beverage vending machine. Relates to a mounting device for mounting the liquid level sensor to the liquid tank.

[0002]

2. Description of the Related Art FIGS. 4 and 5 show examples of the construction of a conventional mounting device 90 for a liquid level sensor 80 of this type.
First, in the liquid level sensor 80, as shown in FIG. 4, an integrated transparent resin case 8 in which a light emitting portion 81 such as an LED and a light receiving portion 82 such as a photodiode are appropriately shaped
3 is formed to be sealed.

When the case 83 is in the liquid, the difference in the refractive index between the member in which the case 83 is formed and the liquid is small, so that the light travels substantially straight at the interface between the two and diffuses into the liquid. Therefore, the light from the light emitting portion 81 does not reach the light receiving portion 82, and therefore, the light is not output to the light receiving portion 82.

Here, when the liquid is consumed and the case 83 is exposed to the atmosphere, a large difference in refractive index is present at the interface between the two (usually, the refractive index of the case 83 is approximately 1.5, and the refractive index of the atmosphere is 1). .0), and the light from the light emitting portion 81 causes total internal reflection at a critical angle or less and reaches the light receiving portion 82. Therefore, the output of the light receiving section 82 is detected to detect the shortage of the liquid.

The liquid level sensor 80 constructed as described above
As shown in FIG. 5, a liquid level sensor 80 is provided at a predetermined position of the liquid tank 20 by a mounting device 90 including a holder portion 91 formed in a substantially cylindrical shape and a mounting fitting portion 92 formed in an L shape, for example. Is held, whereby the liquid level is detected based on the principle described above.

[0006]

In the liquid level sensor 80, as shown in FIG. 6, when the liquid level is lowered and the case 83 is exposed to the atmosphere, a liquid pool W is formed on the surface of the case 83.
Is inevitable. At this time, if all the liquid level sensors 80 are mounted upright in the individual liquid tanks 20 without any mounting error, as indicated by reference numeral (A) in the figure, the liquid level sensors 80 are The influence of the puddle W is also the same, and there is no variation between products.

However, in reality, the symbol (B) in the figure
Alternatively, as shown by the reference numeral (C), it is inevitable that there will be an object that is attached at an angle due to manufacturing errors or the like, and this will cause different effects of the liquid pool W on the light emitting section 81 or the light receiving section 82, and There is a difference in the detection liquid level or the response speed among the products, which causes a decrease in the detection accuracy.

Therefore, the mounting device 90 is required to have high mechanical accuracy and mounting accuracy, which causes a problem that the mounting process is complicated and the cost is increased. However, even if this point is solved, However, if the liquid tank 20 is attached to the main body of the combustion type heater in a tilted state, the same result as if the liquid level sensor 80 is attached in a tilted state is obtained. There has been a problem that the essential detection accuracy cannot be improved only by improving the accuracy and the mounting accuracy, and the solution to this problem has been a problem.

[0009]

As a concrete means for solving the above-mentioned conventional problems, the present invention provides a liquid level sensor held by a holder part on the inner surface of a liquid tank by means of a mounting metal part. In a mounting device for a liquid level sensor, the mounting device is provided with a weight and a universal joint, and the universal joint is provided between the mounting bracket portion and the holder portion. To solve the problem by providing a mounting device for a liquid level sensor, characterized in that the liquid level sensor held by the holder part is displaced in a predetermined direction with respect to the liquid level by the gravity of a weight. Is.

[0010]

EXAMPLES The present invention will now be described in detail based on the examples shown in the drawings. 1 shows a first embodiment of the present invention, and the reference numeral 1 in the drawing denotes a mounting device according to the first embodiment. The mounting device 1 includes a holder portion 2 and a mounting metal fitting portion 3. Is provided, and the liquid level sensor 1 is provided in the holder portion 2.
0 is held and the holder part 2 is attached to the liquid tank 20 by the attachment metal part 3 as in the conventional example.

Here, in the present invention, the attachment device 1 is provided with a weight 4 and a universal joint 5, and by the weight 4 and the universal joint 5, the holder portion 2, that is, the holder. The liquid level sensor 10 held in the portion 2 can be maintained in a predetermined direction with respect to the liquid level of the liquid in the liquid tank 20.

The above-mentioned structure will be described in more detail below. The universal joint 5 includes a mounting member 3 and a holder 2.
In the first embodiment, the universal joint 5 has a rotary shaft 5a formed in a cross shape orthogonal to each other, and both ends of the rotary shaft 5a facing each other. Upper bearing 5b which is rotatably engaged and has a U-shape
And a lower bearing 5c, which is configured as a so-called hook type joint.

At this time, in this first embodiment, the upper bearing 5b is provided with a mounting hole 3a for fixing to the liquid tank 20 and also serves as the mounting metal part 3, and the other lower portion The holder portion 2 is attached to the bearing 5c, and the weight 4 is attached further below the holder portion 2, so that the holder portion 2 is positioned relative to the mounting metal fitting portion 3 in the weight 5c. It is supposed to change along the direction of gravity generated by No. 4 (or the combined direction of gravity and external force, which will be described later).

Next, the operation and effect of the present invention having the above structure will be described. First, since the universal joint 5 is provided between the mounting metal part 3 and the holder part 2, even when the mounting metal part 3 is fixedly mounted on the liquid tank 20, the holder part 2 is fixed to the rotary shaft. 5a makes it possible to rotate simultaneously in two orthogonal directions.

Since the weight 4 is provided below the holder portion 2, the lower bearing 5c of the universal joint 5 has its rotation direction determined by the gravity generated by the weight 4, and thus, if any. At this time, if the weight 4 gives gravity to the lower bearing 5c in the vertical direction, the lower bearing 5c always keeps horizontal with respect to gravity.

This means that the holder portion 2 attached to the lower bearing 5c also keeps the same angle with respect to gravity, so that the liquid level sensor held by the holder portion 2 with the case 11 in a fixed direction. 10 always keeps the case 11 in a constant direction such as the direction of gravity, so that the same mutual relationship is always maintained with the liquid surface in the direction orthogonal to gravity. Of particular importance here is the liquid tank 2
That is, the above mutual relationship is maintained even when a tilt occurs at 0.

Further, in the structure of the universal joint 5 used in the first embodiment, that is, the hook type joint, the upper bearing 5
Since both b and the lower bearing 5c operate on a circular arc having the rotation shaft 5a as the center of rotation, the distance between the mounting metal part 3 and the holder part 2 will be no matter how they operate. Does not change, and therefore does not change the liquid level at which the detection takes place.

Therefore, for example, when the liquid tank 20 is mounted in a tilted state in a production process, that is, when a so-called manufacturing error occurs, or when the entire device including the liquid tank 20 is installed on a sloping ground, it can be said further. For example, even when the degree of inclination of the liquid tank 20 changes momentarily depending on the road surface condition such as an automobile, the mutual angular relationship between the liquid surface and the liquid surface sensor 10 is maintained at a value planned by the designer, and the measurement error or the response is maintained. There shall be no difference in speed.

FIG. 2 shows a second embodiment of the present invention, in which the hook joint is used as the universal joint 5 in the previous first embodiment, whereas in the second embodiment, the ball joint is used. The universal joint 6 is adopted as a joint joint.
The fitting 3 is provided with a through hole 6a and a concave spherical surface 6b, and the concave spherical surface 6b is fitted with a ball portion 6c having the same diameter as the concave spherical surface 6b.

At this time, the ball portion 6c is provided with a shaft portion 6d directed downward and penetrates the through hole 6a. At the same time, the diameter of the through hole 6a is smaller than that of the shaft portion 6d. Since it is large, the ball portion 6c can swing like a pendulum in all directions within the range of the clearance between the through hole 6a and the shaft portion 6d.

As in the first embodiment, the holder 2 is connected to the lower portion of the shaft 6d, and the holder 2 is not shown in the drawing but is similar to the first embodiment. The liquid level sensor is held in a fixed direction, and a weight 4 is provided below the holder 2. The reference numeral 6e in the drawing is a stopper for preventing the ball portion 6c from falling off from the concave spherical surface 6b due to, for example, vibration or impact generated during transportation or use.

In the universal joint 6 of the second embodiment constructed as described above, due to the gravity generated by the weight 4, the concave spherical surface 6b is formed.
And the ball portion 6c slide with each other, so that the holder portion 2 can always maintain a constant angle with respect to gravity, and at the same time, the distance between the mounting metal fitting portion 3 and the holder portion 2 does not change. At this time, in the second embodiment, since the movable portion is located at only one of the concave spherical surface 6b and the ball portion 6c, further simplification of the structure can be expected. The operations and effects other than those described above are the same as those of the first embodiment described above, and thus detailed description thereof is omitted here.

FIG. 3 similarly shows a third embodiment of the present invention. In this embodiment, the universal joint 7 has the mounting fitting 3
The rotation mechanism 7b is rotatably supported by a vertical shaft 7a provided on the rotation mechanism 7b and rotates horizontally, and the horizontal shaft 7c is provided on the rotation mechanism 7b. The holder 2 is rotated by the horizontal shaft 7c. A weight 4 is freely supported and below the holder 2, a weight 4 is provided. With the above-mentioned configuration, also in the third embodiment, the same operation and effect as the first embodiment and the second embodiment can be obtained.

When the gravity generated by the weight 4 is considered again, it is assumed that the liquid tank 20 is stationary in any of the above embodiments, and therefore gravity acts vertically on the ground. I am explaining. However, when the liquid tank 20 is mounted in, for example, an automobile, the direction of gravity generated by the weight 4 does not always act in the vertical direction due to the centrifugal force or acceleration generated as the automobile travels. .

Therefore, in this case, the holder portion 2 does not follow the original direction of gravity, but at the same time the liquid surface also inclines due to centrifugal force or acceleration, so the mutual relationship between the two is liquid. This is exactly the same as when the tank 20 is stationary. Therefore, the configuration of the present invention enables accurate measurement even in the liquid tank of the automobile described above.

[0026]

As described above, according to the present invention, the attachment device is provided with the weight and the universal joint, and the universal joint is provided between the attachment fitting portion and the holder portion, and the gravity of the weight is provided. With the liquid level sensor mounting device configured to displace the liquid level sensor held in the holder portion in a predetermined direction with respect to the liquid level, the mutual relationship between the liquid level sensor and the liquid level is determined by gravity. As the value is automatically set, firstly, the work of mounting the liquid tank and the liquid level sensor is simplified, and the deterioration of the measurement accuracy due to the mounting accuracy is eliminated, and this kind of It is extremely effective in improving the performance of the liquid level sensor.

Secondly, not only the above-mentioned correction of the mounting accuracy between the liquid tank and the liquid level sensor, but also the above-mentioned gravity is corrected when the entire liquid tank is tilted. This enables accurate measurement, expands the application of this type of liquid level sensor, and also enables accurate measurement when a liquid tank such as an automobile moves, which is excellent for further expansion of the liquid level sensor. It has a great effect.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a mounting device for a liquid level sensor according to the present invention.

FIG. 2 is a perspective view showing a second embodiment of a mounting device for a liquid level sensor according to the present invention.

FIG. 3 is a perspective view showing a third embodiment of the same.

FIG. 4 is a sectional view showing a configuration of a liquid level sensor.

FIG. 5 is a perspective view showing a conventional example.

FIG. 6 is an explanatory diagram showing a state of a liquid level sensor and a liquid level.

[Explanation of symbols]

 1 ... Mounting device 2 ... Holder part 3 ... Mounting metal part 4 ... Weight 5,6,7 ... Universal joint 5a ... Rotating shaft 5b ... Upper bearing 5c ... Lower bearing 10 ... Liquid Surface sensor 11 …… Case 20 …… Liquid tank

Claims (4)

[Claims] 1. A mounting device for a liquid level sensor, comprising a mounting part for mounting a liquid level sensor held by a holder part on the inner surface of a liquid tank with a predetermined position and direction. A weight and a universal joint are provided, and the universal joint is provided between the mounting metal fitting portion and the holder portion, and a liquid level sensor held by the holder portion by the gravity of the weight is mounted in a predetermined direction with respect to the liquid surface. A device for mounting a liquid level sensor, characterized in that it is configured to be displaced. 2. The mounting device for a liquid level sensor according to claim 1, wherein the universal joint is a hook type joint. 3. The liquid level sensor mounting device according to claim 1, wherein the universal joint is a ball joint joint. 4. The mounting of a liquid level sensor according to claim 1, wherein the universal joint is configured by a combination of a rotating mechanism having a vertical axis as a shaft and a rotating mechanism having a horizontal axis as a shaft. apparatus.