JPH0320735Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a device for detecting the remaining amount of powder or granular materials such as cement or gravel, or liquid, etc., contained in a silo.

(Prior art and its problems) Conventionally, in order to detect the remaining amount of material stored in a silo, a flexible string wrapped around a winding drum is suspended from the top of the silo into the silo. ,
The length of the droop when the sensing element attached to the lower end reaches the material surface is detected by the number of revolutions of the winding drum. It was not possible to accurately detect the hanging length due to the thickening of the body and the falling of crests, which caused problems in measurement accuracy.

Furthermore, the upper and lower limits of the sensing body can be set by winding and unwinding the flexible string-like body by using the gear ratio of the meshing gear that rotates in conjunction with the rotation of the winding drum to set the upper and lower limits of the limit switch. Since this is done by adjusting the opening/closing point, the gear ratio must be changed depending on the height of the silo, which is cumbersome and time-consuming, and also poses problems in terms of accuracy.

The object of the present invention is to provide a level detection device in a silo that solves these problems.

(Means for Solving the Problems) In order to achieve the above object, the in-silo level detection device according to the present invention has a flexible string-like structure inside the case body 1, as shown in the drawings corresponding to the embodiments. The turn drum 11 rotatably supports the 12 winding drums 5 and the detection drum 7, and is biased upward by a spring force below the detection drum 7.
is arranged to be movable up and down, and the flexible string-like body 12 wound around the winding drum 5 is sequentially stretched around the detection drum 7 and the turn drum 11, and the surface sensing body 13 is attached to the lower end thereof. turn drum 11
In the normal state, the turn drum 11 is moved downward against the spring force.
The upward movement of the flexible string-like body 1 is detected by the detector 17.
The hanging length of the winding drum 5 is detected by the rotation speed of the detection drum 7.
A screw shaft 20 that rotates in conjunction with the rotation of the screw shaft 20 is supported in the case body 1, and a slider 2
3 and 24 are slidably screwed together only in the axial direction, and upper and lower limit setting switches 30 and 31 are disposed at positions where they can approach and separate from the sliders 23 and 24. .

(Function) By rotating the winding drum 5, the flexible string-like body 12
When the flexible string body 12 is rewound and suspended in the silo, the detection drum 7 around which the flexible string body 12 is stretched rotates and its rotational speed is detected, while the lower end of the flexible string body 12 When the surface sensing body 13 attached to the silo reaches the surface of the material in the silo, the weight of the sensing body 13 is received by the material, and the turn drum 11, on which the flexible string-like body 12 is stretched, is moved upward by the spring force. , the hanging length of the flexible string-like body 12, that is, the length of the material, is determined from the rotational speed of the detection drum 7 until the detector 17 is activated and the rotation of the winding drum 5 is stopped. Detect surface position.

Further, the screw shaft 20 rotates in conjunction with the forward and reverse rotation of the winding drum 5, and the sliders 23 and 24 screwed onto the screw shaft 20 move axially to the left or right and hit the switches 30 and 31. By making contact with the winding drum 5, the rotation of the winding drum 5 is stopped, and the upper and lower limits of the surface sensing element 13 attached to the lower end of the flexible string-like body 12 are set. This setting value can be easily changed by adjusting the positions of the sliders 23 and 24 screwed onto the screw shaft 20.

(Example) To explain the example of the present invention with reference to the drawings, 1
is a case body installed on the upper end surface of the silo. A motor 2 is fixed to one side of the inside of the case body. This rotary shaft 3 is connected to a drum shaft 6 rotatably supported by a partition wall 4 of the case body 1. integrally connected, the drum shaft 6
The winding drum 5 fixed to the winding drum 5 is rotated.

7 is a detection drum installed in parallel with the winding drum 5;
The detection drum shaft 8 is rotatably inserted into the partition wall 4,
A rotary encoder 9 is disposed close to the peripheral surface of the shaft 8, and a recess provided in the shaft 8 is detected by the rotary encoder 9 to generate a pulse signal.

Below the detection drum 7, a rotary rod 10 is rotatably supported by the partition wall 4 so as to be able to move up and down, and a turn drum 11 is rotatably supported at the tip of the rotary rod 10.

Reference numeral 12 denotes a flexible string-like material made of steel tape or rope, the base end of which is fixed to the winding drum 5 and wound around the drum.The steel tape is shown in the figure and is approximately the same as this tape. A winding drum 5, a detection drum 7, and a turn drum 11 each having a wide circumferential groove are used.

The flexible string-like body 12 is sequentially stretched from the winding drum 5 to the detection drum 7 and turn drum 11 without winding, and a surface sensing body 13 such as a weight or a float is attached to the tip hanging from the turn drum 11. It is installed.

A central shaft 14 that rotatably supports the turn drum 11 passes through the partition wall 4 so as to be movable up and down, and has a base end pivoted to the inner surface of the partition wall 4 so as to be movable up and down. The lower end of a tension spring 16 whose upper end is fixed to the partition wall 4 or the like is connected to the tip of the rotating rod 15, and the turn drum 11 is urged upward by the spring 16. At the same time, the rotating rod 15 is rotated upward so as to come into contact with a detector 17 consisting of a micro switch for stopping the motor 2.

18 is a limit switch mechanism disposed on the top side of the motor 2, as shown in FIG.
A screw shaft 20 is rotatably installed in the center of the housing 19, and a gear 21 is fixed to the end of the screw shaft protruding from the box 19, and this gear 21 is connected to the motor 2 as shown in FIG. It is meshed with a timing gear 22 fixed to the rotating shaft 3 of.

Further, an upper limit slider 23 and a lower limit slider 24 are screwed onto the screw shaft 20 with an appropriate interval, and these sliders 23 and 24 have a part of their outer periphery inside the box as shown in FIG. The screw shaft 2 is slidably fitted into a straight groove 25 carved in the surface.
It is movable only in the axial direction, and lock bolts 26 and 27 are screwed into appropriate positions on the outer periphery, respectively. 28 is the lock spring of the lock bolt.

Micro switches 30 and 31 for setting upper and lower limits are mounted on the mounting plate 29 of the box 19 so as to face these sliders 23 and 24, respectively, and can be adjusted up and down by a pivot 32. Pieces 33 and 34 are attached to sliders 23 and 2
Adjustment plate 35 is protruded at a position where 4 can come into contact and is attached to the micro switch.
, the adjustment bolt 36 screwed into the mounting plate 29
By rotatably connecting the tips of the adjusting bolts 36 and adjusting the adjusting bolts 36, the contact position of the switch actuating pieces 33, 34 with respect to the slider can be finely adjusted.

Reference numeral 37 designates an adjusting bolt lock spring that is pressed against the adjusting plate 35 and the rod of the mounting plate 29.

To describe the operation of the embodiment configured as above, the flexible string-like body 12 is wound around the winding drum 5 and the surface sensing body 13 is at the upper limit position set by the upper limit setting micro switch 30. As shown in FIG. 2, the turn drum 11 is at position A where it has rotated downward against the spring 16 due to the weight of the surface sensing body 13, and the detector 17
The detector 17 is placed in an ON state so that the motor 2 can operate.

When the start switch of the motor 2 is activated from this state and the motor 2 is rotated in the direction in which the flexible string-like body 12 is fed out, the surface sensing body 13 attached to the lower end of the flexible string-like body 12 is lowered and , the detection drum 7 with the flexible string-like body 12 wrapped around it rotates as the flexible string-like body 12 is fed out, and the rotary encoder 9 generates pulses by the rotation of the shaft 8, and the pulses are measured. The length of the flexible string-like body 12, that is, the descending distance of the surface sensing body 13 is measured from the number of pulses transmitted to a device (not shown).

When the surface sensing body 13 comes into contact with the material surface in the silo, the tensile force applied to the flexible string-like body 12 is reduced, the turn drum 11 is moved upward by the force of the spring 16, and the operating rod 15 becomes the detector. 17, the detector 17 is activated. Surface sensing body 1 during this time
The distance from the top of the silo to the surface of the material in the silo is determined by measuring the descending distance of step 3 as described above.

When the actuating rod 15 comes into contact with the detector 17, the motor 2 is reversed, the flexible string-like body 12 is rewound onto the winding drum 5, and the surface sensing body 13 is pulled up to the upper limit.

When the motor 2 rotates, the meshing gear 21 (22)
through the screw shaft 20 of the limit switch mechanism 18.
rotates, and the upper and lower limit setting sliders 23 and 24 move in the axial direction along the screw shaft 20.

At this time, the lower limit setting slider 24 comes into contact with the lower limit setting micro switch 31 and stops the motor 2 when the surface sensor 13 has descended to a descending distance that confirms that there is no remaining material in the silo. Or, it rotates in the opposite direction, and therefore,
As mentioned above, when the surface sensing element 13 comes into contact with the surface of the material, the lower limit setting micro switch 31 is activated.
It stops just before.

Furthermore, when the motor 2 reverses, the upper limit setting slider 23 moves toward the upper limit setting micro switch 30 (the lower limit setting micro switch also moves integrally).
The motor 2 is stopped when the motor 2 comes into contact with the motor 2.

Incidentally, emergency micro-switches 40, 41 are provided in the box 19 opposite to these micro-switches 30, 31 for setting upper and lower limits in case the micro-switches 30, 31 do not operate.

To adjust the position of the sliders 23, 24 according to the height of the silo, loosen the lock bolts 26, 27, and as shown in FIG.
Ring portion 2 rotatably and fixably fitted to 3a and 24a
This can be done by making the screws 3b and 24b rotatable and moving them in the axial direction of the screw shaft 20 to change the distance from the micro switches 30 and 31. After adjustment, the lock bolts 26 and 27 are tightened.

Further, by rotating the adjuster bolt 36, the contact points of the actuating pieces 33, 34 of the micro switches 30, 31 with the sliders 23, 24 can be finely adjusted, making it possible to finely adjust the upper and lower limits.

(Effect of the invention) As described above, according to the level detection device in a silo according to the present invention, the detection drum has the flexible string-like body 12 with the surface sensing body 13 attached to the lower end arranged separately from the winding drum 5. 7 and the turn drum 11 to detect the descending distance of the surface sensing body 13 by the rotation of the detection drum 7, there is no error caused by the thickening of the flexible string-like body as in the past. The hanging length of the string-like body can be measured with high accuracy, and in addition, the turn drum 11 can be moved up and down, so that it is normally urged upward against the spring force, and the surface sensing body 13 is When it comes into contact with the material surface inside, it is moved upward by the spring force and detected by the detector 17, so that the surface sensing element 13 instantly senses when it reaches the material surface and detects the movement up to that point. This allows the length of the flexible string-like body 13 to be drawn out accurately.

In addition, the sliders 23 and 24 are screwed onto the screw shaft 20 which rotates in conjunction with the winding drum 5 so as to be able to move freely only in the axial direction, and the upper and lower limits can be set at positions where the sliders 23 and 24 can be moved into and out of contact with the sliders 23 and 24. switch 30,
31, these switches 30, 3
By changing the positions of the sliders 23 and 24 with respect to the height of the silo, the upper and lower limit positions of the surface sensing body 13 can be easily and accurately set according to the height of the silo.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a vertical side view, FIG. 2 is a right side view, FIG. 3 is a left side view, and FIG. 4 is a vertical side view of the limit switch mechanism. FIG. 5 is an enlarged sectional view of a portion thereof. 1... Case body, 5... Winding drum, 7...
Detection drum, 11...Turn drum, 12...Flexible string-like body, 13...Surface sensor, 17...Detector, 20...Screw shaft, 23, 24...Slider, 30, 31...Top Lower limit setting switch.

Claims (1)

[Scope of utility model registration request] A winding drum 5 for a flexible string-like body 12 and a detection drum 7 are rotatably supported in the case body 1, and a turn drum 11 is provided below the detection drum 7 and is biased upward by a spring force. A flexible string-like body 12, which is arranged to be movable up and down and is wound around the winding drum 5, is successively passed around the detection drum 7 and the turn drum 11, and turned by the weight of the surface sensing body 13 attached to the lower end of the flexible cord-like body 12. In the normal state, the drum 11 is moved downward against the spring force, and the upward movement of the turn drum 11 is detected by the detector 17, and the hanging length of the flexible string-like body 12 is detected by the detecting drum. Further, a screw shaft 20 that rotates in conjunction with the rotation of the winding drum 5 is supported in the case body 1, and the sliders 23 and 24 are mounted on the screw shaft 20 in the axial direction. The slider 2 is slidably screwed only into the slider 2.
3. A level detection device in a silo, characterized in that upper and lower limit setting switches 30 and 31 are disposed at positions where they can be moved toward and away from the switches 3 and 24.