Electromagnetic pushing-beating-type object-detecting device

Abstract

The invention relates to an object position sensor, in particular to an electromagnetic pushing-beating-type object-detecting device. The device comprises a magnetic pendulum rod, an electromagnet and an electronic module, wherein the electromagnet is arranged on one side of the magnetic pendulum rod and the electronic module controls the electromagnet to drive the magnetic pendulum rod to swing and amplifies, processes and outputs a swinging signal of the magnetic pendulum rod, which is acquired by the electromagnet, in a delayed way; the magnetic pendulum rod is hung on one side of a main body shell by a hanging device; the electromagnet is arranged in the main body shell; the electromagnet consists of an electromagnet core and an electromagnetic coil; the electronic module comprises a power supply circuit, a pulse generating circuit, a pulse driving circuit, a signal amplifying circuit, a signal processing circuit and a signal delaying output circuit; and all the circuits are arranged in the main body shell or isolated from the main body shell for independent encapsulation. The electromagnetic pushing-beating-type object-detecting device has the advantages of high sensitivity, accuracy and reliability, wide application range, no maintenance, long service life and the like.

Description

technical field [0001] The invention relates to a level sensor, in particular to an electromagnetic deduction type object detection device. Background technique [0002] In the application for the patent (99249969.0) of "Single Pendulum Proximity Switch", the applicant once proposed a single pendulum object detection method and device, which uses electromagnets to periodically attract the iron pendulum to make it continuously rotate in the air. It makes a single pendulum movement, and detects the movement state of the pendulum through the material level signal acquisition component. When it swings, it sends out a signal of no material, and when it stops swinging, it sends out a signal of material. After years of application practice, it is found that it has five shortcomings: 1. When installing, it is necessary to ensure that the gap between the pendulum and the electromagnet is between 6-12mm. If the gap is too small, the swing will not be enough; However, it will affect i...

AI Technical Summary

Problems solved by technology

After years of application practice, it is found that it has five shortcomings: 1. When installing, it is necessary to ensure that the gap between the pendulum and the electromagnet is between 6-12mm. If the gap is too small, the swing will not be enough; However, it will affect its normal use; 2. It relies on electromagnetic attraction to drive the pendulum to swing, and the size of its attraction is inversely proportional to the square of the gap between the two. The maximum allowable gap, so the product is relatively bulky, consumes a lot of materials, consumes a lot of power, and the suction is not ideal, so the product cannot be miniaturized, the production cost is high, and it is not conducive to production and transportation; 3. The power consumption cannot be made into The two-wire system is not conducive to the replacement of the two-wire capacitive level switch, and requires a separate swing signal acquisition component, which complicates the structure; 4. Since the direction of the electromagnetic attraction and the adhesion force are consistent, the adhesion becomes easier, so The ability to resist material adhesion is not enough; 5. It cannot withstand high temperature and high pressure

Other commonly used level switches such as rotary resistance, tuning fork, capacitive, radio frequency admittance, and vibrating rod level switches also have their own limitations. Abrasion, corrosion, stuck, and even damage to the motor, resulting in a low service life

Due to the adhesion of materials, the tuning fork type level switch is easy to accumulate material between the tuning forks and stop the vibration, or the long-term vibration may cause mechanical fatigue or broken forks of the tuning forks, and the reliability is not high.

Due to the adhesion of materials, the capacitive or radio frequency admittance level switch is easy to hang on the measuring electrode, resulting in false signals, and the sensitivity is greatly affected by temperature drift and time drift.

The vibrating rod type level switch has a high starting voltage, a long resonance tube, and the piezoelectric element is easily affected by the environment and temperature, and is also easy to break. The sensitivity varies with the material to be detected, and there is a problem of low reliability.

At the same time, there is no ideal product for object detection under harsh working conditions such as high temperature, high pressure, high humidity, and high adhesion.

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