Electromagnet state monitoring device and monitoring method

Abstract

The invention discloses an electromagnet state monitoring device and method. The problem that the current action position state of an existing electromagnet cannot be visually judged is mainly solved. The electromagnet state monitoring device comprises a signal processing board relatively fixed at the corresponding end of the end cap, and a detection board which is perpendicular to the signal processing board and is connected with the signal processing board and is correspondingly embedded in the end cap. The detection plate comprises a magnetic sensor; the signal processing board comprises a signal processing circuit which is correspondingly and electrically connected with the magnetic sensor; the signal processing circuit comprises a comparison unit used for comparing a voltage difference between an output signal of the magnetic sensor and a preset reference voltage, and a signal indication unit correspondingly driven by the voltage difference. Whether the action position of the armature in the electromagnet is in place or not can be intuitively reflected through on-off of the signal indication unit, so that the current state of the electromagnet can be quickly judged, and the troubleshooting and troubleshooting efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnets, and in particular to an electromagnet state monitoring device and method. Background Art

[0002] An electromagnet is a device that generates electromagnetic force when powered on. A coil winding that matches its power is wound around the outside of its iron core. The working principle of an electromagnet is mainly based on the magnetic effect of electric current. When the coil winding is powered on, that is, when the current passes through the wire, a magnetic field is generated around it. This magnetic field magnetizes the iron core, thereby generating an attractive or repulsive force. Then, when the magnetic force at the iron core is greater than the spring force or other resistance on the armature, the armature will move toward the direction of the iron core, thereby completing the closure of the circuit or the action of the mechanical device. When the electromagnet is powered off, the magnetic field disappears, and the armature returns to its original position under the action of the spring force or other reset mechanism, and the circuit is disconnected or the mechanical device is reset.

[0003] Therefore, the position of the armature directly determines the output state of the electromagnet, such as whether it is attracted, whether it is in place, etc. Therefore, accurate detection of the armature state position is the basis for ensuring the normal operation of the electromagnet. By detecting the position of the armature, it is possible to promptly detect whether the electromagnet has a fault or abnormality, such as armature jamming, so as to facilitate timely taking corresponding maintenance or replacement measures to avoid affecting the normal operation of the entire system.

[0004] However, in the process of implementing the technical solution in the embodiments of the present application, the inventors of the present application found that the armature action position of the existing electromagnet cannot be intuitively determined due to the closed shell, which makes it difficult to detect the fault point when a control system fails.

[0005] The information disclosed in this background technology section is only used to deepen the understanding of the background technology of the present disclosure, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art known to those skilled in the art. Summary of the invention

[0006] In view of at least one of the above technical problems, the present disclosure provides an electromagnet state monitoring device and method, aiming to solve the problem that the existing electromagnet cannot timely and intuitively determine the current action position state of the electromagnet.

[0007] According to one aspect of the present disclosure, there is provided an electromagnet state monitoring device, wherein the electromagnet comprises an iron core, a coil wound outside the iron core, an armature coaxially embedded in the end side of the iron core by a guide sleeve, and an end cap for closing the guide sleeve, wherein the electromagnet state monitoring device comprises a signal processing board for being relatively fixed at the corresponding end of the end cap, and a detection board connected and arranged perpendicularly to the signal processing board and correspondingly embedded in the end cap; the detection board comprises a magnetic sensor; the signal processing board comprises a signal processing circuit electrically connected to the magnetic sensor; the signal processing circuit comprises a comparison unit for comparing the voltage difference between the output signal of the magnetic sensor and a preset reference voltage, and a signal indication unit driven correspondingly by the voltage difference.

[0008] In some embodiments of the present disclosure, the signal processing board is fixed to the corresponding end surface of the end cap; and the signal processing board is an annular plate.

[0009] In some embodiments of the present disclosure, slots for inserting the detection board are provided at corresponding positions of the signal processing board.

[0010] In some embodiments of the present disclosure, a blind hole for inserting the detection board is correspondingly opened at the end surface of the end cap.

[0011] In some embodiments of the present disclosure, the magnetic sensor is a TMR sensor or a Hall sensor.

[0012] In some embodiments of the present disclosure, the output terminals V+ and V− of the magnetic sensor are respectively subjected to differential comparison via a differential circuit to obtain the output signal of the magnetic sensor.

[0013] In some embodiments of the present disclosure, a voltage follower is correspondingly connected between the output terminal of the magnetic sensor and the input of the differential comparison circuit.

[0014] In some embodiments of the present disclosure, the signal processing board also includes a voltage-stabilizing power supply chip for generating the preset reference voltage.

[0015] According to another aspect of the present disclosure, there is provided an electromagnet state monitoring method, which is implemented based on the above-mentioned electromagnet state monitoring device, and increases or decreases the coil voltage according to the control requirements, and judges the action state of the armature according to the signal display state of the signal indication unit (such as the lighting of the indicator light, the sound of the buzzer, etc.).

[0016] In some embodiments of the present disclosure, the coil corresponds to a loading current direction that satisfies the output V of the magnetic sensor. + −V ->0, and the armature is judged to be actuated according to the corresponding signal status displayed by the signal indicating unit (such as the on and off of the indicator light, the sound of the buzzer, etc.).

[0017] One or more technical solutions provided in the embodiments of the present application have at least any of the following technical effects or advantages: the signal indication state of the signal indication unit (such as the on and off of the indicator light, the sound of the buzzer, etc.) can intuitively reflect whether the action position of the armature inside the electromagnet is in place (or stuck), which helps to quickly determine the current state of the electromagnet and improve the efficiency of fault inspection and troubleshooting. Further, the detection board corresponding to the magnetic sensor is embedded in the blind hole opened at the end cap of the electromagnet, so that the magnetic sensor at the detection board is relatively closer to the armature, which greatly improves the detection accuracy. In addition, the detection board is arranged perpendicular to the signal processing board and embedded in the slot at the signal processing board, thereby ensuring the electrical connection between the magnetic sensor and the signal processing circuit, while increasing the distance between the magnetic sensor and the signal processing circuit, reducing the electromagnetic interference caused by the signal processing circuit, and further improving the measurement accuracy of the magnetic sensor; at the same time, only a blind hole matching the detection board and having a relatively small structure volume needs to be opened at the end cap, thereby reducing the adverse effect of the detection board installation on the end cap structural strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of a partial structure of an electromagnet state monitoring device in one embodiment of the present application.

[0019] Figure 2 is a circuit schematic diagram of a signal processing circuit in an embodiment of the present application.

[0020] Figure 3 This is a curve diagram of the sensor output signal under different air gaps in an embodiment of the present application.

[0021] In the above figures, 11 is a magnetic sensor, 12 is a detection PCB board, and 2 is a signal processing board. DETAILED DESCRIPTION

[0022] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside", "vertical", "horizontal", "clockwise", "counterclockwise", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0023] In order to better understand the technical solution of the present application, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0024] In order to solve the problem that the existing electromagnet action position is difficult to directly observe, and the current electromagnet armature action position cannot be quickly determined when facing systematic maintenance or troubleshooting, this example discloses an electromagnet state monitoring device. In this embodiment, the electromagnet includes an iron core, which is used to be magnetized after electromagnetic induction and correspondingly generate electromagnetic attraction or repulsion. One end of the iron core is coaxially connected with a guide sleeve, which is in the shape of a hollow tube sleeve and fixed to one end of the iron core; the guide sleeve is embedded with an armature, wherein the length of the guide sleeve is greater than the length of the armature, thereby ensuring that the armature can move along the axial direction of the guide sleeve in the guide sleeve, and relatively approach or move away from the iron core by relying on the electromagnetic attraction or repulsion generated at the iron core, thereby generating the action of the electromagnet. In addition, the outer edge of the guide sleeve is correspondingly wound with a coil, which is used to cooperate with the iron core to generate electromagnetic induction after power is turned on, and the corresponding magnetized iron core. In this example, the coil is wound outside the guide sleeve through a skeleton, and the skeleton plays a role in supporting and protecting the coil. In addition, in order to prevent the armature from slipping out of the guide sleeve, an end cap is installed at the other end of the guide sleeve to seal the end of the guide sleeve, thereby protecting and limiting the armature.

[0025] In order to detect the state of the electromagnet, i.e. the action of the armature, in this embodiment, the electromagnet state monitoring device includes a signal processing board and a detection board. The detection board performs relative detection of the action position of the armature, and the detection signal is processed by the signal processing board and then outputs corresponding information to reflect the action information of the electromagnet. Specifically, in this example, see Figure 1 The detection board includes a magnetic sensor 11 and a detection PCB board 12, wherein the detection PCB board 12 is used as a carrier of the magnetic sensor 11 for welding and fixing the magnetic sensor 11. According to the characteristic that the internal magnetic field of the electromagnet changes when the armature moves, the change of the magnetic field of the electromagnet is captured by the magnetic sensor 11, thereby reflecting the movement of the armature. In this example, the magnetic sensor adopts a TMR sensor. In some other embodiments, the magnetic sensor adopts a Hall sensor. The magnetic field signal collected by the magnetic sensor, that is, the output signal of the magnetic sensor, is further output to the signal processing board for signal processing.

[0026] The signal processing board 2 includes a signal processing PCB board and a signal processing circuit welded on the PCB board. Among them, the inventor of the present application found in the long-term practice and research process that there is a specific corresponding relationship between the output signal of the magnetic sensor and the coil voltage. When the coil voltage increases from 0V to the rated voltage, near the moment when the armature position suddenly changes, the output signal of the magnetic sensor suddenly changes, and its output voltage increases sharply at a relatively fast speed and then tends to be relatively flat. Similarly, when the coil voltage decreases from the rated voltage to 0V, near the moment when the armature position suddenly changes, the output signal of the magnetic sensor also suddenly changes, and its output voltage decreases sharply at a relatively fast speed and then tends to be relatively flat. Based on this discovery and combined with long-term practical experience, the applicant realizes that the output voltage of the magnetic sensor can be used to judge whether the armature of the electromagnet has moved into place, thereby realizing real-time working status monitoring of the electromagnet.

[0027] In this embodiment, the signal processing circuit at the signal processing board 2 includes a comparison unit, through which the output signal of the magnetic sensor is compared with a preset reference voltage to obtain a voltage difference between the two, and the preset reference voltage is used as a judgment basis to judge that the output signal of the magnetic sensor greater than the preset reference voltage is a qualified armature action position, that is, the armature is judged to be in place. At the same time, in order to intuitively reflect the voltage difference between the magnetic sensor and the preset reference voltage signal, in this embodiment, the signal processing circuit also includes a signal indication unit, and the signal indication unit includes an LED lamp, thereby, the LED lamp is driven to emit light by the voltage difference between the magnetic sensor and the preset reference voltage signal, and whether the armature is in place is judged by the on and off of the LED lamp body.

[0028] For details, see Figure 2 In this example, the comparison between the output signal of the magnetic sensor and the preset reference voltage is realized by the comparison unit in the signal processing circuit. The comparison unit is specifically an operational amplifier U5, and the output signal of the magnetic sensor and the preset reference voltage are respectively used as inputs of the operational amplifier U5. Figure 2, the output pins of the magnetic sensor U1 include V+ and V-, and the differential voltage between the two pins corresponds to the output signal of the magnetic sensor U1. For this reason, an operational amplifier U4 is set to perform differential operation to improve the anti-interference ability. In this embodiment, the two output pins of the magnetic sensor U1 are electrically connected to the corresponding input terminals of the operational amplifier U4 through the voltage follower U2 and the voltage follower U3 respectively, and the buffering and impedance matching are realized by the voltage follower. Therefore, the output of the operational amplifier U4 is used as the effective output signal of the magnetic sensor, which is electrically connected to the input terminal of the operational amplifier U5 and compared with the preset reference voltage, so as to determine whether the armature position corresponding to the magnetic field strength reflected by the current signal of the magnetic sensor is the required position. In order to intuitively observe the comparison result between the output signal of the magnetic sensor and the preset reference voltage, in this embodiment, the output terminal of the operational amplifier U5 is correspondingly connected to a signal indicating unit including an LED lamp, i.e., a light emitting diode, and the voltage difference between the magnetic sensor and the preset reference voltage corresponds to driving the LED lamp to emit light, so that when the output signal voltage of the magnetic sensor is greater than the preset reference voltage, the LED lamp emits light, and when the output signal voltage of the magnetic sensor is less than the preset reference voltage, the LED lamp goes out.

[0029] Therefore, the magnitude of the preset reference voltage reflects the qualified armature action position of the electromagnet, that is, when the output signal voltage of the magnetic sensor is greater than the preset reference voltage, the armature action is in place and qualified, meeting the control requirements. In this embodiment, a voltage-stabilized power supply chip is set as a voltage-stabilized power supply for the signal processing circuit to stably provide 3.3V DC power. In order to realize the setting of the preset reference voltage, see Figure 2 The inverting input terminal of the operational amplifier U5 is connected to a sliding rheostat SW1, and the input voltage of the inverting input terminal of the operational amplifier U5 is adjusted by adjusting the resistance value of the sliding rheostat SW1 connected to the circuit, thereby achieving the purpose of presetting the reference voltage.

[0030] In this embodiment, in order to determine a reasonable preset reference voltage, the distance between the armature and the core along the armature axis is taken as the air gap. The air gap is at its maximum value at the initial moment, when the armature is far away from the core. When the electromagnet coil is powered on, the armature is attracted by the magnetized core and moves along the guide sleeve until it contacts the core, which is the minimum value of the air gap. By setting gaskets of different thicknesses in the air gap space, the final action position of the armature is controlled, and the output signal of the magnetic sensor is measured under gaskets of different thicknesses. The result curve is shown in Figure 3, the horizontal axis in the figure is the coil voltage, and the vertical axis is the sensor output signal. The curves in the figure correspond to gaskets with gradually increasing thickness from top to bottom, that is, the final position of the armature action gradually moves away from the end face of the core, among which the top curve corresponds to the situation where the air gap is not blocked. Therefore, in this example, the preset reference voltage is selected as 1.2V. When the coil voltage increases to the rated voltage, the preset reference voltage is between the magnetic sensor output signal voltages corresponding to the unobstructed and blocked air gaps, respectively, so that the preset reference voltage is not less than the magnetic sensor output signal corresponding to the armature when it moves into place, avoiding the preset reference voltage being too large and losing its reference significance, and at the same time avoiding the preset reference voltage being too small and causing the situation where there is an air gap between the armature and the core to be misjudged as the armature moving into place, thereby ensuring the referenceability of the preset reference voltage.

[0031] In addition, in this embodiment, the signal processing board is fixed to the outer end surface of the end cap. Considering that it is convenient for the manual resetting of the electromagnet armature, a resetting hole is provided at the end cap. In order to prevent the signal processing board from affecting the resetting function of the resetting hole, see Figure 1 In this example, the signal processing board 2 is a ring board. Figure 1 In this example, the detection board 12 is arranged perpendicular to the signal processing board 2, and a slot matching the width of the detection board is provided at the signal processing board 2. One end of the detection board is inserted into the slot, and the detection board is electrically connected to the circuit at the signal processing board through the solder joint at the end of the detection board inserted into the slot, thereby realizing the electrical connection between the magnetic sensor of the detection board and the signal processing circuit at the signal processing board. In addition, in order to realize the installation of the detection board at the end cap, a blind hole matching the contour of the detection board is opened at the end face of the end cap relative to the fixed signal processing board in this example, so that the detection board is inserted into the blind hole. Therefore, on the one hand, since the detection board is embedded in the end cap, the magnetic sensor at the detection board is closer to the armature, which helps to improve the detection accuracy; on the other hand, the detection board is arranged perpendicular to the signal processing board, so that the distance between the magnetic sensor and the signal processing circuit is relatively far, which helps to reduce the electromagnetic interference generated by the signal processing circuit; in addition, since the detection board is relatively small in volume, the hollow volume at the end cap is smaller than the volume of the signal processing circuit also arranged at the detection board, which helps to improve the structural strength of the end cap.

[0032] In addition, this example also discloses an electromagnet state monitoring method implemented based on the above-mentioned electromagnet state monitoring device. When the electromagnet state monitoring is performed based on the electromagnet state monitoring device, the coil voltage is first controlled according to the required action of the electromagnet, and specifically a control current is input into the connection terminal of the electromagnet coil to drive the electromagnet to act. At the same time, the magnetic sensor of the electromagnet state monitoring device obtains electromagnetic information at the electromagnet in real time. Therefore, when the electromagnet is controlled by the energized coil and moves under the attraction of the iron core and the action is in place, the output signal of the magnetic sensor is greater than a preset reference voltage signal. At this time, the voltage difference between the two drives the LED lamp to light up, and the armature movement can be judged to be in place based on the lighting of the LED lamp; and when there is a gap between the end point of the armature movement and the iron core, that is, the armature movement is not in place, because the output signal voltage of the magnetic sensor is less than the preset reference voltage at this time, the LED lamp does not light up. Based on this, whether the electromagnet armature movement is in place is judged based on the on and off of the LED lamp of the signal indication unit.

[0033] In this embodiment, when current is applied to the coil, the direction of the applied current is controlled, that is, the electrical connection relationship between the positive and negative electrodes of the power supply and the positive and negative terminals of the coil is controlled, so that the output of the magnetic sensor satisfies V + −V - >0, to avoid the problem that the positive and negative terminals of the electromagnet coil are reversed, affecting the output signal of the magnetic sensor and causing it to reverse, thereby preventing the electromagnet from operating normally and in place, while the output signal of the magnetic sensor cannot be greater than the preset reference voltage, resulting in the signal indication unit failing to light up and losing the electromagnet status indication effect.

[0034] Although some preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0035] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of this application and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. An electromagnet state monitoring device, the electromagnet comprising an iron core, a coil wound outside the iron core, an armature coaxially embedded on the end side of the iron core by a guide sleeve, and an end cap for closing the guide sleeve, characterized in that: The electromagnet state monitoring device comprises a signal processing board fixed relatively to the end corresponding to the end cap, and a detection board connected and arranged perpendicularly to the signal processing board and correspondingly embedded in the end cap; The detection board includes a magnetic sensor; the signal processing board includes a signal processing circuit electrically connected to the magnetic sensor; The signal processing circuit includes a comparison unit for comparing a voltage difference between an output signal of the magnetic sensor and a preset reference voltage, and a signal indication unit driven corresponding to the voltage difference.

2. The electromagnet state monitoring device according to claim 1, characterized in that: The signal processing board is fixed correspondingly to the end surface of the end cap; and the signal processing board is an annular plate.

3. The electromagnet state monitoring device according to claim 1 or 2, characterized in that: A slot hole for inserting the detection board is provided at a corresponding position of the signal processing board.

4. The electromagnet state monitoring device according to claim 1, characterized in that: A blind hole for inserting the detection board is correspondingly opened at the end surface of the end cap.

5. The electromagnet state monitoring device according to claim 1, characterized in that: The magnetic sensor is a TMR sensor or a Hall sensor.

6. The electromagnet state monitoring device according to claim 1, characterized in that: The output terminals V+ and V- of the magnetic sensor are respectively compared with each other through a differential circuit to obtain the output signal of the magnetic sensor.

7. The electromagnet state monitoring device according to claim 6, characterized in that: A voltage follower is correspondingly connected between the output terminal of the magnetic sensor and the input of the differential comparison circuit.

8. The electromagnet state monitoring device according to claim 1, characterized in that: The signal processing board also includes a voltage-stabilizing power supply chip for generating the preset reference voltage.

9. A method for monitoring the state of an electromagnet, characterized in that: The electromagnet state monitoring device according to claim 1 is implemented to increase or decrease the coil voltage according to the control requirements, and to judge the action state of the armature according to the signal display state corresponding to the signal indication unit.

10. The electromagnet state monitoring device according to claim 9, characterized in that: The direction of the current loaded on the coil satisfies the output V of the magnetic sensor. + −V - >0, and the armature is judged to be actuated according to the corresponding signal status displayed by the signal indication unit.

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