Switch electromagnet

Abstract

The utility model discloses a switch electromagnet which mainly solves the technical problem that the final action position of an existing switch electromagnet is difficult to accurately judge. The fixed iron core is provided with an action cavity along the axis, the movable iron core is correspondingly embedded in the action cavity, the coil is wound outside the fixed iron core, the end cap is arranged on the corresponding end side of the fixed iron core and used for blocking the action cavity, and the position detection piece is embedded in the end cap. The position detection member comprises a TMR switch, a power supply port which is correspondingly and electrically connected with a power supply pin of the TMR switch, and an indication diode which is electrically connected between the power supply port and an output pin of the TMR switch. According to the switch electromagnet, the action position of the movable iron core can be rapidly and reliably judged, normal work judgment can still be achieved when the coil is reversely connected, and limitation on coil wiring of the switch electromagnet is avoided.

Description

Technical Field

[0001] This application relates to the field of electromagnet technology, specifically to a switching electromagnet. Background Technology

[0002] Switching electromagnets, as important electrical control components, have wide applications in industrial automation, machinery, and electronic equipment. Specifically, a switching electromagnet is a device that uses electromagnetic force to control the on / off state of a circuit. It consists of an electromagnet part and a switching part. The electromagnet part includes a coil and an iron core, while the switching part includes a moving contact and a stationary contact. When the coil is energized, the stationary iron core is magnetized, generating a magnetic field that attracts the moving iron core to close the stationary contact, thus connecting the circuit. When the coil is de-energized, the magnetism of the stationary iron core disappears, and the moving iron core separates from the stationary contact under the action of a return spring, thus disconnecting the circuit.

[0003] The coil is typically made of enameled wire, with the number of turns and wire diameter determined by the required electromagnetic attraction and operating voltage. When the coil is energized, it generates a magnetic field, attracting the movable iron core. The fixed iron core is the core component of the switching electromagnet, usually made of soft iron or silicon steel. Under the influence of the magnetic field, the fixed iron core is magnetized, generating an attractive or repulsive force, which in turn drives the movable iron core. Furthermore, the return spring is an important auxiliary component of the switching electromagnet, used to quickly reset the moving contact when the coil is de-energized. The spring force and size of the return spring are determined by the required reset speed and operating force.

[0004] However, in the process of implementing the technical solution in the embodiments of this application, the inventors of this application found that when the existing electromagnet is switched on and off, the movement trajectory of its internal movable armature cannot be directly observed, making it difficult to determine whether the actual position of the movable armature is in place, thus causing difficulties in fault diagnosis and repair.

[0005] The information disclosed in this background section is intended only to enhance the understanding of the background technology of this disclosure and should not be construed as an admission or in any way implying that the information constitutes 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, this disclosure provides a switching electromagnet, which mainly solves the technical problem that existing switching electromagnets are difficult to accurately determine their final operating position.

[0007] According to one aspect of this disclosure, a switching electromagnet is provided, comprising a fixed iron core having an actuation cavity along an axis, a movable iron core correspondingly embedded in the actuation cavity, a coil wound around the fixed iron core, an end cap at a corresponding end of the fixed iron core for sealing the actuation cavity, and a position detection element embedded in the end cap; the position detection element includes a TMR switch, a power supply port electrically connected to a power supply pin of the TMR switch, and an indicator diode electrically connected between the power supply port and an output pin of the TMR switch.

[0008] In some embodiments of this disclosure, the end cap has a blind hole of a certain depth along the axial direction of the fixed iron core for embedding the position detection element.

[0009] In some embodiments of this disclosure, a current-limiting resistor is also connected in series between the power supply port and the output pin of the TMR switch.

[0010] In some embodiments of this disclosure, filter capacitors are connected in parallel between the power supply ports.

[0011] In some embodiments of this disclosure, the TMR switch is a unipolar TMR switch or an all-polar TMR switch.

[0012] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0013] 1. The TMR switch enables accurate and reliable detection of the position of the movable iron core. The circuit structure is simple and the cost is low. The indicator diode can be used to quickly determine whether the movable iron core is in position at the current moment, which can greatly improve the efficiency of maintenance and troubleshooting.

[0014] 2. The position of the movable iron core is detected by using an all-pole TMR switch. It can work normally and output even when the coil is reversed, which breaks through the limitation of the wiring of the switching electromagnet coil and greatly facilitates the wiring and use of the switching electromagnet. Attached Figure Description

[0015] Figure 1 This is a partial structural schematic diagram of a switching electromagnet in one embodiment of this application.

[0016] Figure 2 This is a circuit diagram of a position detection device in one embodiment of this application.

[0017] Figure 3 The image shows the response curve of a unipolar TMR switch in one embodiment of this application.

[0018] Figure 4 This is a magnetic field strength curve at the position detection device in one embodiment of this application.

[0019] Figure 5 The output curve of a unipolar TMR switch in one embodiment of this application is shown.

[0020] Figure 6 The response curve of an all-polar TMR switch in another embodiment of this application is shown.

[0021] Figure 7 This is a magnetic field strength curve at the position detection device in another embodiment of this application.

[0022] Figure 8 The output curve of an all-polar TMR switch in another embodiment of this application is shown.

[0023] In the above figures, 1 is the fixed iron core, 2 is the movable iron core, 3 is the coil, 4 is the end cap, 5 is the position detection component, 51 is the TMR switch, 52 is the power supply port, 53 is the indicator diode, 54 is the current limiting resistor, and 55 is the filter capacitor. Detailed Implementation

[0024] In the description of this application, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," "outer," "vertical," "horizontal," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "connection" and "linkage" in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0025] Unless otherwise specified, all devices and other components involved in the following embodiments are commercially available products.

[0026] To better understand the technical solution of this application, the above technical solution will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] To address the problem that existing electromagnets make it difficult to determine whether the movable armature has moved to the correct position, thus hindering maintenance and troubleshooting, this example discloses a switching electromagnet that enables convenient, low-cost, and highly accurate detection of the movable armature's movement.

[0028] See details Figure 1The switching electromagnet disclosed in this example includes a fixed iron core 1 and a movable iron core 2. In this example, the fixed iron core 1 has a cylindrical structure, and a deep actuating cavity is formed at one end of the fixed iron core 1 along its axis. The outer contour of the movable iron core 2 matches the inner contour of the actuating cavity, thus allowing the movable iron core 2 to be fitted into the actuating cavity of the fixed iron core 1 during use, and to move along the axis of the actuating cavity, i.e., the fixed iron core 1, under the action of electromagnetic force, thereby realizing the switching action of the electromagnet.

[0029] In order for the movable iron core 2 to perform switching actions according to control requirements, see [link to relevant documentation]. Figure 1 In this example, a coil 3 is wound around the outer edge of the fixed iron core 1, and both ends of the coil 3 are electrically connected to the power supply. Thus, when the coil 3 is powered on, the current passing through the coil will generate a magnetic field around the coil, and the direction of the magnetic field is related to the direction of the current. As a result, the fixed iron core 1 and the movable iron core 2 set in the coil are magnetized and become magnets with opposite polarities. An electromagnetic attraction is generated between them, attracting the movable iron core 2 to move along the moving cavity inside the fixed iron core 1. When the coil current is cut off, the magnetic field around the coil disappears. The magnetism of the fixed iron core 1 and the movable iron core 2, which are made of soft magnetic material, dissipates rapidly after the surrounding magnetic field disappears. Then, under the reset action of the reset spring, the movable iron core 2 returns to the initial position.

[0030] However, during the operation of the movable iron core 2, there may be jamming or other issues, preventing the movable iron core 2 from moving to its designated position during the opening or closing action, leading to a malfunction of the switching electromagnet. Furthermore, during troubleshooting or repair, the current position of the internal movable iron core 2 is not visible due to the surrounding casing of the switching electromagnet, making troubleshooting difficult, time-consuming, and inefficient. Therefore, in this embodiment, see... Figure 1 A position detection element 5 is provided at the end cap 4 of the switching electromagnet. The position detection element 5 detects the position of the movable iron core 2 and determines whether it has reached the correct position. Specifically, the end cap 4 is used to seal and fix the operating cavity port on the end side of the iron core 1, preventing the movable iron core 2 from dislodging from the operating cavity when subjected to electromagnetic force or spring reset force, and facilitating the inspection and replacement of the movable iron core 2. In this embodiment, a blind hole of a certain depth is formed on the outer edge of the end cap 4, and the position detection element 5 is embedded in the blind hole. In other embodiments, the depth of the blind hole is greater than the length of the position detection element 5, so that the position detection element 5 can be completely embedded in the blind hole, ensuring the stability of the position detection element after the blind hole is sealed later.

[0031] To achieve the position detection effect of position detection component 5, in this embodiment, see... Figure 2The position detection component 5 includes a TMR switch 51 and a power supply port 52. The TMR switch 51 includes a positive power supply pin (Vdd), a ground pin (GND), and an output pin (Vout). The two terminals of the power supply port 52 are electrically connected to the corresponding power supply pins (Vdd and GND) of the TMR switch 51, respectively, to reliably supply power to the TMR switch. In this embodiment, the TMR switch 51 is specifically a unipolar TMR switch; its corresponding curve is shown in [reference needed]. Figure 3 As shown, the TMR switch 51 has a sensitive direction, determined by... Figure 3 It can be seen that when the magnetic field strength in the sensitive direction exceeds the operating point B... OP When the magnetic field strength in the sensitive direction gradually decreases and falls below the release point B, the TMR switch outputs a low level; when the magnetic field strength in the sensitive direction gradually decreases and falls below the release point B, the TMR switch outputs a low level. RP When the TMR switch is active, it outputs a high level; thus, the operating point B is used as the reference point. OP and B RP As the critical operating point, the TMR switch can respond to different magnetic field strengths. Therefore, in this embodiment, when the movable iron core 2 performs a switching action, the magnetic field at the same point around it changes with the movement of the movable iron core 2. The magnetic field strengths at the points when the movable iron core 2 is in its final position and when it is reset are considered as operating points B. OP and B RP Therefore, when the movable iron core 2 moves, the output of the TMR switch can be used to determine whether the movable iron core 2 has moved to the correct position.

[0032] To ensure that the output of the TMR switch 51 can simply, accurately, and conveniently reflect whether the movable iron core 2 has reached its designated position, in this embodiment, see... Figure 2 An indicator diode 53 is placed between the power supply port 52 and the output pin Vout of the TMR switch 51. Specifically, this indicator diode 53 is a light-emitting diode (LED). One end of the diode is connected to the positive power supply, and the other end is connected to the output pin of the TMR switch. Therefore, when the TMR switch outputs a low level, the indicator diode 53 is forward-biased and illuminates; when the TMR switch outputs a high level, the indicator diode 53 is reverse-biased and extinguishes. Thus, the on / off state of the indicator diode allows for an accurate and simple determination of whether the movable iron core 2 has reached its designated position. Furthermore, see [link to other documentation]. Figure 2 In this embodiment, to prevent the indicator diode 53 from burning out due to excessive voltage, a current-limiting resistor 54 is connected in series in the branch where the indicator diode is located. In addition, a filter capacitor 55 is connected in parallel between the power supply ports to avoid the adverse effects of power fluctuations on the position detection device.

[0033] See Figure 1Taking the direction along the axis of the fixed iron core 1 as the z-direction, and assuming the gap between the movable iron core 2 and the fixed iron core 1 is Gap, then after applying a +24V voltage to the coil, as the movable iron core 2 moves, the magnetic field strength curve at the position detection device is shown in the figure. Figure 4 The blue curve in the figure represents the component of the magnetic field strength in the z-direction, showing that the magnetic field strength changes with the gap. Furthermore, in this example, the operating point is set to B. OP The value is 7mT, and the operating point is B. RP The current is 5.5mT, and the supply voltage of the TMR switch is 3.3V. Figure 5 As can be seen from the output curve of the TMR switch as the magnetic field strength changes, when the gap is less than 1mm, it is considered that the movable iron core has reached the designated position, and the TMR switch outputs a high level. When the gap is greater than 1mm, it is considered that the movable iron core has not reached the designated position, and the TMR switch outputs a low level. Therefore, the level of the TMR switch output can be used to determine whether the movable iron core has moved to the designated position.

[0034] Further research by the inventors revealed that existing switching electromagnets have stringent requirements regarding the direction of the current in the coil. When the coil is reversed, causing a change in the current direction, the magnetic field established by the energized coil will also reverse, rendering the aforementioned unipolar TMR switch unable to detect the movement. Therefore, in some other embodiments, to avoid the adverse effects of coil reversal on the detection of the movable core's position, in this example, the TMR switch in the position detection device is an all-polar TMR switch, and its response curve can be found in [reference needed]. Figure 6 As shown, the all-polar TMR switch has a corresponding output whether the surrounding magnetic field is in the same direction as or opposite to its sensing direction. This solves the problem that the TMR switch cannot output when the coil is reversed, causing the surrounding magnetic field to reverse. To verify the effectiveness of this all-polar TMR switch, in this embodiment, a +24V voltage is applied to the switch electromagnet coil. The magnetic field strength around its position detection element and the output of the TMR switch are compared. Figure 4 and Figure 5 The corresponding curves are the same; when a -24V voltage is applied to the coil of the switching electromagnet, the magnetic field strength around its position detection element is shown in the figure. Figure 7 As shown, the corresponding TMR switch output can be found in the image. Figure 8 As shown, even if the coil is reversed, it does not affect the output of the all-pole TMR switch, allowing the position detection device to work reliably under both positive and negative magnetic fields.

[0035] Although some preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0036] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of its inventive concept. Therefore, if such modifications and variations to this disclosure fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A switching electromagnet, characterized by The position detection piece includes a TMR switch, a power supply port electrically connected with a power supply pin of the TMR switch, and an indication diode electrically connected between the power supply port and an output pin of the TMR switch.

2. The switch solenoid of claim 1, wherein The end cap is provided with a blind hole of a certain depth along the axial direction of the fixed core and used for embedding the position detection piece.

3. The switch solenoid of claim 1, wherein A current limiting resistor is connected in series between the power supply port and the output pin of the TMR switch.

4. The switch solenoid according to claim 1 or 3, characterized in that A filter capacitor is connected in parallel between the power supply ports.

5. The switch solenoid of claim 1, wherein The TMR switch is a single-pole TMR switch or a full-pole TMR switch.

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