RU2521130C1 - Liquid level sensor - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: invention relates to devices for liquid level monitoring and can be used to monitor the level of various liquids in apparatuses, tanks and vessels of stationary and movable installations. The essence of the invention consists in the fact that the cavity of a float is filled by grains with low substance density, for example, by foamed polyethylene, joint of the sensor and the tank is made as a bayonet coupling providing for exact positioning of the float rotation axis in the horizontal position, and different length of the grooves in the bayonet coupling prevents the sensor from being installed incorrectly.

EFFECT: provision for sensor operability in case of leakage in a float, exact vertical positioning of a float in the course of sensor installation.

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Description

The invention relates to devices for controlling the level of a liquid and can be used to control the level of various liquids in apparatuses, containers and vessels of stationary and mobile installations.

Known switches with magnetically controlled contacts with the angular movement of the magnet relative to the fixed reed switch (Kharazov K.I. Switches with magnetically controlled contacts. - M .: Energy, 1978, p. 44-45). Reed switch - an abbreviation for "sealed (magnetically controlled) contact" - an element that mechanically closes or opens an electric circuit with a proper change in magnetic field strength. In horizontal float level switches, a float with a magnet is hinged, and the reed switch is located in the sensor housing. In this case, the level switch is mounted in the side wall of the tank. When the liquid reaches the sensor level, the magnet acts on the reed switch and the circuit closes.

Crydom reed switches of the RSF series horizontal design are known from the prior art (the design is similar to that described in K.I. Kharazov Automation Devices with Magnetically Controlled Contacts. - M .: Energoizdat, 1990, p. 215-216).

Liquid level sensors are structurally composed of a movable magnet, which is moved by the float, and magnetically sensitive reed contacts. The reed switch is triggered when the magnet approaches, the sensor gives a switching signal. When the liquid level decreases, the magnet lowers, returning the contacts to their original position.

The disadvantages of the Crydom liquid level sensor include the fact that the sensor is attached to the tank using a threaded connection without strictly fixing the position of the axis of the float in a horizontal position.

A liquid level switch is known (autoswitch No. 1742628, class G01F 23/56), in which a float with a magnet installed on it moves along a vertical non-magnetic pipe and the reed switch is switched on, which is recorded as a change in the liquid level.

A significant drawback of this detector is the ambiguity of information about the liquid level. So, when a magnet exits from interaction with a reed switch, it is impossible to unambiguously determine whether the liquid level has risen or decreased. In addition, the sensor does not provide control of the limits of regulation of the liquid level.

A known liquid level sensor (patent US 6195013 B1, class G08B 21/00) having floats, magnet, reed switch, electrical connector and bayonet connection for securing the sensor to the tank.

The disadvantage of this sensor is the design complexity, in particular, the sensor design requires vertical installation, the presence of the pipe in which the floats are located, and the use of several floats.

The closest in technical essence to the claimed one is a Crydom liquid level sensor (prototype), including a threaded housing, a reed switch, a magnet and a float with angular movement of the magnet relative to a fixed reed switch.

The disadvantages of the prototype include the fact that when installing the sensor when using threads, it is necessary to set the axis of rotation of the float in a horizontal position, the complexity of the design does not ensure reliability in operation when the float is leaking, the installation is not technologically advanced.

The problem solved by the invention is to increase the manufacturability of the installation of the sensor and increase the reliability of operation.

Effect: installation and fixation of the sensor in a position where the axis of rotation of the float is oriented horizontally; sensor fixation is ensured by the use of rubber o-rings; reliability in operation is ensured when the float is leaking.

The technical result is achieved by the fact that the sensor float is prefabricated, the float is filled with granules with a low density of the substance, for example, foamed polyethylene, the sensor is connected to the tank in the form of a bayonet connection, the axis of the float is installed in a horizontal position, and the sensor is fixed with o-rings. The possibility of improper installation of the sensor is eliminated by using different lengths of the arc of the groove of the bayonet connection and protrusions of different widths in the tank body.

Filling the cavity of the float with granules with a low density of the substance ensures the reliability of the sensor during operation in case of violation of the integrity of the float. The bayonet connection of the sensor with the tank provides ease of installation of the sensor and serves for the exact horizontal location of the axis of rotation of the float. Different length of the arc of the groove of the bayonet connection eliminates the installation of the sensor in the wrong position. O-rings are used to fix and seal the sensor with a container.

Figure 1 and figure 2 shows a diagram of a liquid level sensor.

The sensor consists of:

- pads pos. 1 (the connector pads are similar to the pads connector 282101-1 AMP Superseal 1,5 SRS), which has contacts pos. 9, and the sealing ring pos. 6 installed on the landing part of the pads;

- housing pos.2 with a magnetically controlled contact unit located in the cavity of the housing - reed switch pos.8 and sealing rings pos.5 installed on the housing;

- a float cap pos. 3 with an installed magnet pos. 7 and filled with granules pos. 10 with a low density of substance and a cap cap pos. 4 having axial guides pos. 12 in the housing pos. 2 to ensure free movement of the float, and a stopper pos. 13 limiting the maximum deflection angle of the float;

- bayonet connection pos.11 of the sensor with a capacitance pos.14 with the lengths of the arc grooves on the sensor housing α and β and the corresponding protrusions on the container body with the lengths of the arcs 7 and 6.

The sensor is installed in the side wall of the expansion tank with coolant or tank. The sensor must provide opening and closing of the DC electric circuit of not more than 1A with a rated voltage of 12V and not more than 0.5A with a rated voltage of 24V, as well as when the voltage changes from 90 to 125% of the nominal value. The closure of the sensor contacts should occur independently when the coolant level is reduced, determined by the risk “min”, and not have “false” responses when braking the car and driving on rough roads. The reed contact zone is 20 ° max.

In float type liquid level sensors, reed switches are used as a switching element. When the liquid reaches the sensor placement level, the float with a built-in magnet rises with the liquid level and closes or opens the contacts of the reed switch.

Thus, the inventive liquid level sensor provides a more accurate determination of the liquid level, easier to install and more reliable.

Claims (1)

The liquid level sensor containing a block with a connector, a housing with a reed switch, a float with a magnet installed, characterized in that the float is prefabricated, the float is filled with granules with a low density of the substance, the connection of the sensor with the tank is made in the form of a bayonet connection, the axis of the float is set to horizontal and the sensor is fixed with o-rings, the connection of the sensor with the capacitance is made in the form of a bayonet connection with a different length of the groove arc.

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