JPH06174527A - Level detecting apparatus - Google Patents

Abstract

PURPOSE:To facilitate maintenance by forming the inner wall surface of a housing in a funnel shape, and maintaining the airtightness of the housing. CONSTITUTION:The lower part of a case 21 from the central part is formed in a funnel shape. An opening part 24, which is formed at the lower side is set so that the inner diameter is larger than the outer diameter of a weight 6. An attaching part 22 has a hole 54, whose inner diameter is equal to the opening part 24. The attaching part 22 is attached to a tank 8 through a packing so that the airtightness of the case 21 is maintained. In this constitution, even if powder rises up toward the opening part 24, enters the case 21 and piles up on the inner wall surface, the powder slides and falls into the tank 8 when the certain degree of the load is reached. When a belt 7 is replaced, the weight 6 is lifted up into the case 21 through the opening part 24 and removed from the case 21. Then, the belt 7 is removed from a winding drum 10, and the new belt 7 is attached to the drum 10 and housed in the case 21. The weight 6 is suspended in the tank 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a level detecting device for measuring the level of powder, granules, etc. stored in a tank.

[0002]

2. Description of the Related Art A conventional level detecting device of this type will be described with reference to FIGS. In FIG. 7, reference numeral 1 denotes a housing, which is composed of a base plate 2, a cover 3, and a lid 4, which are fitted to each other and whose fitting portion is screwed. In addition, a cylindrical mounting portion 5 for mounting this device on the upper wall of the tank 8 is provided on the lower surface of the base plate 2, and the hollow portion of the cylindrical mounting portion 5 has a weight 6 at the tip.
The belt 7 attached with is moved up and down. In addition,
The inside of the housing 1 and the inside of the tank 8 are communicated with each other through the hollow portion of the cylindrical mounting portion 5, but the gap formed between the side surface of the hollow portion and the belt 7 is set to be extremely small. Thus, the powder or the like in the tank 8 is prevented from entering the housing 1.

Next, an outline of a mechanism for vertically moving the weight 6 attached to the tip of the belt 7 will be described with reference to FIG. In FIG. 8, reference numeral 9 is a motor that is normally rotated and reversed by a driving means (not shown). Then, when the belt 7 comes into contact with the bottom surface in the engagement groove formed on the circumferential surface of the pulley by the frictional force due to the action of the weight 7, and the belt 7 is displaced while rotating the count pulley 11, Rotate accordingly. Reference numeral 12 denotes a pulse transmitter, which detects the number of rotations of the count pulley 11 by a plurality of magnets 13 fixed to the side surface of the count pulley 11 at equal intervals.

Reference numeral 14 is a stopper provided at the tip of the belt 7 for winding, and 15 is a winding completion rod.
By being pushed up from below by the stopper 14, the winding completion lever 16 is rotated by a predetermined angle,
Further, the switch 18 is turned on in cooperation with the winding completion cam 17. Reference numeral 19 denotes a chain for attaching the weight 6 to the stopper 14 provided at the lower end of the belt 7 via the attachment metal fitting 50.

In such a structure, the count pulley 11 faces toward the surface of the object to be measured, which is the object stored in the tank 8.
By lowering the weight 6 while rotating, the weight 6 reaches the surface of the object to be measured, but at that time, the motor 9 still continues to rotate, so the belt 7 sags, and the count pulley 11 The measurement ends when is no longer rotating. After that, the motor 9 is rotated in the reverse direction and the stopper 14 at the tip of the belt 7 is wound up upward,
When the stopper 14 at the tip of the belt 7 hits the winding completion rod 15, the belt 7 is wound around the winding drum 10 via the winding completion lever 16 and the winding completion cam 17 until the switch 18 is turned on.

[0006]

However, in such a level detecting device, when a stored object such as powder is pumped into the tank 8 by using air pressure, the base plate 2 and the case. 3. Since the airtightness of the joint surface between the lid 4 and the lid 4 is not sufficient, the air in the tank 8 leaks out from the joint surface, and accordingly powder and the like is formed between the cylindrical mounting portion 5 and the belt 7. There is a problem in that the powder is fed into the housing 1 through the created gap and the powder is filled in the housing 1.

Further, since this kind of level detecting device is usually installed outdoors, thick paint should be applied from the upper side of the mounting bolt so that the mounting bolt for mounting the level detecting device on the tank 8 will not be rusted and maintenance becomes impossible. When changing the belt or cleaning the inside of the housing in order to apply the paint, it is necessary to remove the detector after removing the paint, which requires a lot of time and maintenance. There was a problem that the cost was much higher.

The present invention has been made in view of such problems, and an object thereof is to facilitate maintenance.

[0009]

In a level detecting device according to the present invention, a belt having a weight attached to its tip and a drum for winding the belt are housed in a housing and attached to an upper wall surface of a tank. In the level detecting device for detecting the level of the stored item by vertically moving the weight in the tank according to the vertical displacement of the surface of the stored item, the inner wall surface of the housing is formed in a funnel shape. And, the airtightness is maintained.

[0010]

In the device according to the present invention, the air in the tank is prevented from leaking from the inside of the housing due to the airtightness of the housing, so that the powder or the like does not enter the housing. It drops along the tapered surface.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.
1 to 7 are views showing an embodiment of the present invention. In FIGS. 1 to 7, the same components as those described in FIGS. 7 and 8 or equivalent components are denoted by the same reference numerals, and the description thereof will be omitted. Only different points will be described.

A packing 20 is interposed between an end surface of an opening of a case 21 described later and the lid 4, and when the lid 4 is fastened to the case 21 with a bolt 23, air in the tank 8 is removed. Prevents leakage to the outside. As shown in FIG. 2, the case 21 has a funnel shape from the center to the lower side, and the opening 24 formed at the lower end of the case 21 has an inner diameter larger than the outer diameter of the weight 6. . Reference numeral 22 denotes an attachment portion attached to the lower end of the case 21, and a hole 54 having the same inner diameter as the opening 24 of the case 21 is bored so that the case 21 is kept airtight with respect to the tank 8. It is attached via a packing (not shown).

The case 21 is constructed as described above.
The powder soars toward the opening 24 formed at the lower end of the case and enters the case 21.
Even if they are deposited on the inner wall surface of No. 1, when they are loaded to some extent, they slide down on the caper surface (the funnel-shaped portion of the inner wall surface of the case 21) and enter the tank 8.

In addition, when the belt 7 is to be replaced,
As shown in, the weight 6 is pulled up into the case 21 through the opening 24 at the lower end of the case 21, taken out of the case 21, and then the pin 51 of the mounting bracket 50 is pulled out (see FIG. 5).

Next, the winding drum 10 is removed from the drum spindle 53 connected to the rotary shaft of the motor 9 by removing the mounting bolts 52 thereof (see FIG. 6), and FIG.
The belt 7 is removed from the winding drum 10 as shown in FIG. 4, the new belt 7 is wound as shown in FIG. 4, attached to the winding drum 10, stored in the case 21, and the weight 6 is suspended in the tank 8 for replacement. The work is finished.

[0016]

As described above, according to the present invention, the case is not filled with powder, and the maintenance work for cleaning can be eliminated. Further, even when the belt is replaced, the powder does not adhere to the case, so that the workability can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view of a level detecting device according to an embodiment of the present invention.

FIG. 2 is an operation explanatory view of a process of replacing the belt 7.

FIG. 3 is an explanatory diagram of an operation for removing the belt 7 from the winding drum 10.

FIG. 4 is an explanatory diagram of an operation for attaching the belt 7 to the winding drum 10.

FIG. 5 is a work process explanatory diagram when the weight 6 is removed from or attached to the belt 7.

FIG. 6 is a work explanatory diagram when the winding drum 10 is removed or attached.

FIG. 7 is an explanatory diagram of a conventional level detection device.

FIG. 8 is a schematic explanatory diagram for explaining the mechanism of the level detection device.

[Explanation of symbols]

 20 packing 21 case 22 mounting portion 24 opening

Claims (1)

[Claims] 1. A belt having a weight attached to a tip thereof and a drum for winding the belt are housed in a housing, mounted on an upper wall surface of a tank, and the weight is contained in the tank. In a level detection device for detecting the level of the stored items by moving up and down according to the vertical displacement of the surface, the inner wall surface of the housing is formed in a funnel shape, and the housing is kept airtight. Characteristic level detection device.