Magnetic object position sensor

Abstract

This utility model relates to switching technology, specifically to devices capable of detecting the presence of a ferromagnetic object in a sensitive area. The technical result consists of a sensor insensitive to vibration and ambient temperature changes, capable of determining the position of magnetic objects. The sensor for detecting a magnetic object comprises a housing made of a non-magnetic material containing a stationary magnetic system and a magnetically controlled element—a reed switch. The magnetic system consists of two flat magnets, with opposite poles facing each other and arranged with a gap between them, and the reed switch is located in the plane of symmetry of the magnetic system. The presence of a stationary magnetic system and the absence of damping fluid in the housing ensure the sensor is independent of vibrational and temperature effects on the sensor housing. 3 Fig.

Description

[0001] This utility model relates to the field of switching technology, specifically to devices that detect the presence of a ferromagnetic object in a sensitive area. This allows the utility model to be used in the creation of sensors and various object positioning systems used in robotics, security alarms, control and measuring equipment, automated transport security systems, mechanical engineering, metallurgy, and other fields of human activity where it is necessary to use one or more sensors to determine the position of objects made of magnetic materials or non-magnetic materials with attached magnetic tags.

[0002] A sensor for determining the position of an object made of magnetic material is known from the prior art according to patent RU 126191 U1, which includes a housing made of a non-magnetic material, a magnet that creates a constant magnetic field, at least one magnetically controlled element located in at least one plane, characterized in that the housing additionally contains a chamber with a lid filled with a damping liquid, and the permanent magnet is made in the form of a body of revolution (in the form of a ball, in the form of a cylinder, in the form of a disk, in the form of a ring) with diametrical magnetization, placed in the chamber and rotating freely in at least one plane.

[0003] The disadvantages of this sensor are:

[0004] Presence of damping fluid. As the ambient temperature drops, the viscosity of the fluid increases, requiring significantly more time for the magnet to rotate, and therefore for the sensor to respond, than under normal climatic conditions;

[0005] absence of factors that return the magnet to the neutral position when removing an object made of ferromagnetic material from the sensitive area of ​​the sensor;

[0006] Vibration or mechanical shock may cause the magnet to move uncontrollably in the damping fluid and, as a result, cause the sensor to trigger falsely;

[0007] The magnetically controlled element, usually a reed switch, is itself a ferromagnet and will cause the magnet to turn with its pole towards itself, initiating a false triggering of the sensor.

[0008] The magnetic position sensor of JSC NPK TEKO MS GR2P-31-L is known 2 , which is designed for contactless switching of electrical circuits of actuators in industrial automated devices, lines, machines, and systems. The sensor is designed for operation in explosion-proof environments free of aggressive gases and vapors in concentrations that can corrode metals. It incorporates a magnetically controlled reed switch, which changes the contact state when a steel (ferromagnetic) plate is introduced into the sensor's sensitivity zone.

[0009] The disadvantages of this sensor are increased requirements for installation, tolerances for misalignment of the plate and the gap in the switch housing, limitations on the shape of the controlled surface - the ferromagnetic element of action should not be thicker than the gap on either side of which the reed switch and magnet are located, and the width of the gap, in turn, is limited by the magnitude of the magnet induction and the magnetomotive force of the reed switch.

[0010] The prototype of the claimed technical solution is a device for determining the position of an object made of magnetic material according to patent RU 2510888 C1, comprising a housing made of a non-magnetic material, a magnet that creates a constant magnetic field, at least one magnetically controlled element located in at least one plane, characterized in that the housing additionally contains a chamber with a lid filled with a damping liquid, and the permanent magnet is made in the form of a body of revolution (in the form of a ball, in the form of a cylinder, in the form of a disk, in the form of a ring) with diametrical magnetization, placed in the chamber, freely rotating in at least one plane.

[0011] The disadvantages of this sensor are:

[0012] Presence of damping fluid. As the ambient temperature drops, the viscosity of the fluid increases, requiring significantly more time for the magnet to rotate, and therefore for the sensor to respond, than under normal climatic conditions;

[0013] absence of factors that return the magnet to the neutral position when an object made of ferromagnetic material is removed from the sensitive area of ​​the sensor;

[0014] Vibration or mechanical shock may cause the magnet to move uncontrollably in the damping fluid, resulting in false triggering of the sensor.

[0015] The objective of the technical solution is to create a sensor in a housing made of a non-magnetic material, containing a magnetic system and a magnetically controlled element - a reed switch, devoid of the disadvantages of analogs and the prototype, namely:

[0016] the presence of a stationary magnetic system, the change of position of which relative to the magnetically controlled element - the reed switch - is not required for the operation of the sensor and the position of which does not change under vibration and mechanical influences on the sensor;

[0017] no need to use damping fluid due to the use of a stationary magnetic system, which means that the sensor characteristics, in particular the sensor response time, are independent of the ambient temperature.

[0018] The problem is solved by the fact that the magnetic system consists of two flat magnets, turned towards each other with opposite poles and located with a gap between them, and the magnetically controlled element - the reed switch - is located in the plane of symmetry of the magnetic system.

[0019] The technical result of the claimed solution is a sensor in a housing made of a non-magnetic material without a damping fluid, containing a stationary magnetic system and a magnetically controlled element - a reed switch, capable of changing the state of the magnetically controlled element of the reed switch when an object made of a ferromagnetic material appears in its sensitive zone, insensitive to vibration and changes in ambient air temperature.

[0020] The general appearance of the sensor is shown in Fig. 1, where in the sensor housing 1 there is a magnetic system consisting of two flat magnets 2, having magnetization through the short side, turned towards each other with opposite poles, and a reed switch 3, located in the plane of symmetry of the magnetic system.

[0021] When there is no object made of ferromagnetic material in the sensitive area of ​​the sensor, the magnetic field is symmetrical relative to the magnetic system and the reed switch is in the off state as shown in Fig. 2.

[0022] When an object made of ferromagnetic material appears in the sensitive area of ​​the sensor, as shown in Fig. 3, the magnetic field is drawn towards the object, the neutral plane of the field no longer coincides with the plane of symmetry of the magnetic system, and the reed switch is in the zone of influence of one of the magnets and switches to the on state.

[0023] Sources of information taken into account

[0024] 1. Utility model patent RU 126191 U1 "Sensor for determining the position of an object made of magnetic material", copyright holder Limited Liability Company "Control Technologies Pilot Production", published on March 20, 2013.

[0025] 2. Magnetic position sensor TEKO MS GR2P-31-L, https: / / teko-com.ru / , copyright holder Joint-Stock Company Scientific and Production Company "TEKO".

[0026] 3. Patent for invention RU 2510888 C1 "Method for determining the position of an object made of magnetic material and a device for implementing it", copyright holder Limited Liability Company "Control Technologies Pilot Production", published on 10.04.2012.

Claims

A sensor for detecting an object made of a magnetic material, comprising a housing made of a non-magnetic material containing a magnetic system and a magnetically controlled element - a reed switch, characterized in that the magnetic system is stationary, consists of two flat magnets, turned towards each other with opposite poles and located with a gap between them, and the magnetically controlled element - the reed switch is located in the plane of symmetry of the magnetic system.

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