RU104706U1 - FLOAT SIGNAL - Google Patents

Abstract

 1. A float switch comprising a float with a lever, rotatable around a horizontal hinge, a magnet installed inside the float, a nozzle with a float stop and a reed switch installed with the possibility of being switched on from a magnet, the hinge axis is perpendicular to the magnetization axis of the magnets, and the float with a lever and the hinge is connected with the fitting, characterized in that the lever is made in the form of an open continuation of the length of the pipe float, a magnet is installed inside the float, additionally introduced into the fitting a magnetic screen mounted on the reed switch, a printed circuit board and a terminal block, a connecting thread is made at the end of the fitting for installing a sealing plug or cable entry. ! 2. The float switch according to claim 1, characterized in that the semiconductor active switch is additionally installed on the printed circuit board.

Description

The proposed utility model relates to the field of control and regulation of the liquid level.

Known liquid level switches type MS 10 manufactured by K-Tek [1], a series of switches type NW1-020HM and RW-015HKS manufactured by Honsberg [2], liquid level sensors-switches POC400 and FX406 [3], liquid level switches [4] ] operating on the principle of threshold float transducers that have a sensing element in the form of a float with rotary movement and a system of electrical contacts working using magnetic coupling and triggered by the corresponding movement of the float with a built-in permanent magnet The effect of the buoyancy force of a liquid on a float. These float transducers are installed on the side wall of the tank at a height corresponding to the signaling level, and have relatively small dimensions. The use of magnetic coupling in threshold float converters makes it possible to contactlessly transfer the actuating force from the float to the contacts laid out in the form of reed switches through an impermeable wall of non-magnetic material. The liquid level switch, made on the indicated principle, has a float, a permanent magnet rigidly connected to it, a hinge, limiters of maximum displacements of the float in the form of plates, a membrane of non-magnetic material, made in the form of a single unit with a mechanical sealing element - a fitting containing a mounting flange and contact switching mechanism - reed switch.

However, such a signaling device is complex in design and not reliable enough due to the presence of a large number of welded elements using resistance welding.

Closest to the proposed technical solution is a mini-float level switch type FD МН46 (prototype) [5], it contains a float, a permanent magnet rigidly connected to it, which is built into the lever, hinge, limiters of maximum displacements of the float in the form of a plate fasteners, fitting made of non-magnetic material, made in the form of a single compound-sealed device containing a mounting flange and a sealed contact switch - reed switch.

The disadvantage of the prototype is the increased complexity of manufacture and low reliability due to the use of fastening of the components of the float by contact welding, there is no protection of the reed switch against inrush currents, unrepairability, high cost.

This goal is achieved by the fact that a float detector containing a fitting made of non-magnetic material and a reed switch installed in it contains: a magnetic screen mounted on the reed switch, a printed circuit board and a terminal block. The device is sealed using a threaded connection located at the end of the fitting, which is designed to install a plug or cable entry. In addition, the float indicator includes a float with a lever made of a piece of a single non-magnetic pipe with a magnet integrated inside the float. The float is connected to the fitting with a hinge made of an open segment of the pipe of the lever of the float and a non-magnetic metal pin. When the float emerges, the reed and magnet axes coincide. Due to the use of the magnetic shield of the reed switch, the sensitivity zone of the latter is narrowed, which ensures a higher accuracy of operation. The terminal block allows you to simplify the installation of the device on the site.

Entering into the device according to claim 2 a semiconductor active key increases the reliability of the device by increasing the resource of the reed switch, which in this case operates in low current mode and is additionally protected from inrush currents that occur when switching the load.

The design of the proposed float switch is shown in the drawing (Figure 1).

The float switch contains a fitting 1 with a reed switch 2 installed in it with a magnetic shield 3, a printed circuit board 4, with a terminal block 5 mounted on it, and a float 6 with a lever made from a segment of a non-magnetic pipe. A magnet 7 is built into the float, which, when the float 6 is floating, is on the same axis as the reed switch 2 of the fitting 1. The hinge is made of a pin 8 and an open length of the pipe of the float 2. The float 6 is connected to the fitting 1 by means of a hinge.

In the device according to claim 2, a semiconductor active key is additionally installed on the printed circuit board 4.

The device operates as follows.

There is no fluid in the initial state. The float 6 of the indicator is in the lowest position. In this case, the float rests against the protrusion of the nozzle 1 on the side of the hinge 1. The magnet 7, which is installed inside the float 6, is outside the zone of interaction with the reed switch 2, the active zone of which is narrowed by installing a magnetic shield 3. When the liquid level rises, the buoyant force applied to the float 6 and directed vertically upwards, raises the float 1. When the magnet 7 of the float 6 reaches the sensitivity angle of the reed switch 2, the latter is switched on. Signal output is maintained even with a further increase in liquid level. When this float 6 is fixed in horizontal position by the internal cavity of the lever of the float 6.

In the float switch according to claim 2, when using a semiconductor active key that acts as a buffer amplifier, a tripped reed switch 2 puts the key in the open state.

Improving the reliability of the device is achieved by:

- the use of fewer connected mechanical elements;

- the use of a semiconductor active switch that ensures the operation of the reed switch in low current mode, which increases the last resource and protects the reed switch from inrush current during inductive load switching;

In the design of the float switch, standard materials are used - a reed switch type MKA101, a pipe and a hexagon made of non-magnetic material and a semiconductor active switch (Smart Power Switch) type BSP75.

Information sources:

1. Installation and operation manual for MS 10..

2. Technical description of signaling devices of the NW1-020HM and RW-015HKS series. www. .

3. Technical description of POS400 and FX406 signaling devices. .

4. Liquid level switch. Patent for invention RU No. 2292016, class. G01F 23 / 38-2007.

5. Mini float level switch FD MH46. http: file: ////www.fine-tek.com.

Claims (2)

1. A float switch comprising a float with a lever, rotatable around a horizontal hinge, a magnet installed inside the float, a nozzle with a float stop and a reed switch installed with the possibility of being switched on from a magnet, the hinge axis is perpendicular to the magnetization axis of the magnets, and the float with a lever and the hinge is connected with the fitting, characterized in that the lever is made in the form of an open continuation of the length of the pipe float, a magnet is installed inside the float, additionally introduced into the fitting a magnetic screen mounted on the reed switch, a printed circuit board and a terminal block, a connecting thread is made at the end of the fitting for installing a sealing plug or cable entry. 2. The float switch according to claim 1, characterized in that the semiconductor active switch is additionally installed on the printed circuit board.