A self-locking device for electromagnetic mechanism of AC contactor

Abstract

The invention is used for a self-locking device of an electromagnetic mechanism of an AC contactor. In the initial position, the locking plate is not in the slot position and is limited by the limiting body at the top of the main iron core. The lever presses the travel switch to keep it closed. When AC power is passed into the main coil, the main iron core is attracted, the limiting body extends upward, the locking plate moves to the slot position and is locked in the slot, the reset spring pulls the lever to rotate counterclockwise in the opposite direction, the travel switch is released, and the main coil loses power. However, due to the action of the locking plate and the slot, the main iron core is locked in the attracted position. At this time, the auxiliary coil has no power, and the auxiliary iron core is in a free state and is lifted with the lever; when released, the power supply in the coil working circuit is cut off, the auxiliary coil receives the instruction signal and quickly attracts, the auxiliary iron core is pulled downward, the lever rotates positively clockwise, the locking plate is disengaged from the slot, the main iron core is reset, the lever presses the travel switch to close, and the main coil is restored to the initial position. The structure is simple and compact, the attraction and release process is simple and reliable, the operation is convenient, the stability is good, and there is no current loss.

Description

Technical Field

[0001] The invention relates to a self-locking device for an electromagnetic mechanism of an AC contactor. Background Art

[0002] Electrical switches and other equipment used for power transmission and distribution, such as AC contactors, often use various types of electromagnetic mechanisms composed of coils, iron cores, reset devices, etc.; but in many cases, the coil needs to be continuously powered after it is attracted to maintain the normal working state of the electromagnetic mechanism. For example, when the electromagnetic mechanisms such as AC contactors, electromagnetic control and protection switches are in the attracted position during the working process, the coil needs to be continuously powered to maintain the attracted state; traditional electromagnetic mechanisms have complex structures, high energy consumption due to continuous power supply, and the coil is prone to burnout when powered on for a long time, with poor reliability, and the mechanism is prone to failure when encountering sudden interference conditions; and the auxiliary interlocking functions provided by other mechanical structures are mostly complex in structure, inconvenient to operate, and difficult to ensure reliability. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a self-locking device for the electromagnetic mechanism of an AC contactor which can maintain self-locking in the electromagnetic mechanism's attracted state, has a simple and compact structure, low energy consumption, simple and reliable attraction and release processes, and is easy to operate.

[0004] The present invention is used for the self-locking device of the electromagnetic mechanism of the AC contactor, comprising an electromagnetic mechanism composed of a main coil and a main iron core, characterized in that: a limiting body is fixedly connected to the top of the main iron core, and the diameter of the connecting section between the limiting body and the main iron core is smaller than the limiting body, forming a slot; when the main coil is energized and attracted, the limiting body extends upward with the main iron core, and when the main coil is de-energized, the limiting body retreats downward with the main iron core under the action of an internal reset mechanism (including a reset spring, etc.); a mounting seat is fixedly installed on the main coil bracket, a lever is installed above the mounting seat through a hinge shaft, a locking plate that can swing with the lever is connected to the middle of the lever, the locking plate is located on one side of the main iron core, when in the self-locking position, the locking plate can swing in the reverse direction and snap into the slot to lock the main iron core, and when in the initial position, the limiting body can limit and support the locking plate, so that the lever presses a travel switch in the coil working circuit of the main coil to keep the coil working circuit conductive; one end of the lever is connected to an instantaneous driving mechanism that can instantly press the lever to swing forward, and the other end of the lever is connected to a reverse reset spring;

[0005] The instantaneous driving mechanism includes an auxiliary electromagnetic coil and an auxiliary iron core driven to extend and retract by the auxiliary electromagnetic coil, and the auxiliary iron core is connected to the lever; when the instantaneous current is passed, the instantaneous auxiliary iron core can complete a positive swinging action of pressing the lever once;

[0006] The return spring is connected between the rear end of the lever and the mounting seat, and the mounting seat is also provided with a limiting surface capable of limiting the reverse swing stroke of the lever;

[0007] The instantaneous drive mechanism and the travel switch are both fixedly mounted on the mounting seat;

[0008] The upper part of the auxiliary core has a neck with a smaller diameter, and the lever is plugged into the neck through a U-shaped slot at the end. When the auxiliary core is attracted, the lever can be pulled by using the limit position of the neck;

[0009] The reverse return spring is a tension spring, and the travel switch is a micro switch;

[0010] The main coil has a control circuit, which includes a coil working circuit and a control circuit; the coil working circuit includes the main coil and the travel switch K1 connected between the AC power input terminal; the control circuit includes a rectifier circuit connected to the AC power input terminal, and the control unit, the auxiliary electromagnetic coil and the charging capacitor are connected between the two poles of the DC output terminal of the rectifier circuit to form a DC charging and discharging circuit; the control unit can control the charging and discharging and time of the charging capacitor.

[0011] The invention is used for a self-locking device of an electromagnetic mechanism of an AC contactor. In the initial position, the locking plate is not in the slot position and is limited by the limiting body at the top of the main iron core. The lever presses the travel switch to keep it closed. When AC power is passed into the main coil, the main iron core is attracted, the limiting body extends upward, the locking plate moves to the slot position and is locked in the slot, the reset spring pulls the lever to rotate counterclockwise in the opposite direction, the travel switch is released, and the main coil loses power. However, due to the action of the locking plate and the slot, the main iron core is locked in the attracted position. At this time, the auxiliary coil has no power, and the auxiliary iron core is in a free state and is lifted with the lever; when released, the power supply in the coil working circuit is cut off, the auxiliary coil receives the instruction signal and quickly attracts, the auxiliary iron core is pulled downward, the lever rotates positively clockwise, the locking plate is separated from the slot, the main iron core is reset, the lever presses the travel switch to close, and the main coil is restored to the initial position. The structure is simple and compact, the attraction and release process is simple and reliable, the operation is convenient, the stability is good, and the energy consumption is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the planar structure of a self-locking device for an electromagnetic mechanism of an AC contactor according to an embodiment of the present invention;

[0013] Figure 2 1 is a schematic cross-sectional structural diagram of a self-locking device for an electromagnetic mechanism of an AC contactor in an embodiment of the present invention when the self-locking device is in an initial position;

[0014] Figure 3 It is a schematic cross-sectional structure diagram of a self-locking device for an electromagnetic mechanism of an AC contactor according to an embodiment of the present invention after being locked in a closed state;

[0015] Figure 4 is a circuit diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0016] As shown in the figure, a self-locking device for the electromagnetic mechanism of an AC contactor has a main structure that adopts a conventional electromagnetic mechanism composed of a main coil 1 and a main iron core 8. The main iron core 8 is extended by the main coil 1, or retracted inwardly under the action of a reset mechanism composed of a reset spring inside the main coil 1, to perform an opening or closing action.

[0017] In this embodiment, a cylindrical limit body 8 extending upwardly along the same axis is connected to the top end of the main iron core 8, the diameter of the connecting section between the limit body 8 and the main iron core is smaller than the limit body 8, and the diameter of the connecting section between the limit body 8 and the main iron core is smaller than the limit body, forming a slot 81. When the main coil 1 is energized and attracted, under the action of electromagnetic induction force, the limit body 8 extends upward with the main iron core. When the main coil loses power, the limit body 8 retreats downward with the main iron core under the action of an internal reset mechanism (including a reset spring, etc.).

[0018] A mounting seat 5 is fixed above the bracket of the main coil 1. The mounting seat 5 is roughly a U-shaped structure, and is fixedly mounted and connected to the bracket of the main coil 1 through the bottom plate of the U-shaped structure. A notch is set in the middle of the bottom plate of the mounting seat 5 so that the limit body can extend or retract upward with the main iron core 8; a vertical upward limit baffle 51 is set at one end of the U-shaped structure of the mounting seat 5, and a micro switch is fixedly installed on the inner side of the baffle 51 to form a travel switch 6, and an auxiliary electromagnetic coil 2 is fixedly installed on the outer side, and an auxiliary iron core 3 is set inside the auxiliary electromagnetic coil 2 to form an instantaneous drive Mechanism; a transverse lever 7 is arranged above the mounting seat 5, and the middle part of the lever 7 is hingedly connected to the mounting seat through a hinge shaft; a locking piece 71 that can swing with the lever 7 is fixedly connected to the other side of the hinge shaft 9 relative to the travel switch 6. When in the self-locking position, the locking piece 71 swings counterclockwise in the opposite direction to be able to snap into the slot 81 to lock the main iron core. When in the initial position, the outer circumferential surface of the limit body 8 can limit and support the locking piece 71, so that the lever 7 presses the travel switch 6 in the coil working circuit of the main coil 1 to keep the coil working circuit conductive;

[0019] A neck section with a smaller diameter is arranged on the upper part of the auxiliary iron core 3, so that a limiting pressure block 4 is formed above the top of the auxiliary iron core, and a circular open limiting groove is arranged at the end of the lever 7 corresponding to the limiting pressure block 4 to form a U-shaped slot. The lever 7 is connected to the neck below the limiting pressure block 4 through the U-shaped slot in cooperation with the limiting card. When the auxiliary electromagnetic coil 2 is instantaneously actuated, the limiting step on the upper part of the limiting pressure block 4 presses the lever 7 to swing forward around the hinge shaft 9; a reverse reset spring 10 composed of a tension spring is connected to the other end of the lever 7. When the lever 7 swings forward, the reverse reset spring is stretched by force, and the lever 7 can be pulled to reset in the reverse direction by the elastic restoring force of the reverse reset spring 10.

[0020] The travel switch 6 is connected to the coil working circuit of the main coil 1. When the lever 7 swings forward, the travel switch 6 is pressed to control the coil working circuit of the main coil L1 to be closed and turned on. When the lever 7 swings reversely, the coil working circuit is turned off.

[0021] Furthermore, the upper end limit of the reverse reset spring 10 is fixed to the end of the lever 7, and the lower end limit is fixed to the side wall of one side of the U-shaped structure of the mounting seat 5. The part of the side wall on the other side of the U-shaped structure of the mounting seat 5 corresponding to the reverse reset spring 10 constitutes a limit structure 51 for reverse reset of the lever 7.

[0022] Furthermore, the travel switch 6 is fixedly mounted on the bottom plate of the mounting seat inside the baffle 52, which has a compact structure and occupies little space.

[0023] The control principle of the embodiment of the present invention is as follows: Figure 2 As shown, the mechanism is in the initial position before working. When the limiting body 8 is in the initial position, it retracts into the main coil 1 along with the main iron core. The main coil 1 loses power and the entire mechanism is in a power-free state. The auxiliary coil 2 also loses power, the auxiliary iron core 3 is in a free state, the lever 7 is connected to the upper end of the auxiliary iron core 3, the locking piece 71 is not in the position of the slot 81, and is limited by the limiting body 8. The lever 7 cannot rotate, and at the same time, the reset spring 10 is pulled, and the travel switch 6 is pressed and closed by the lever 7.

[0024] When the switch needs to be closed, AC is passed through the main coil 1, the limiter 8 extends upward with the main iron core, the locking piece 71 moves to the position of the slot 81 and is locked in the slot 81, the lever 7 rotates counterclockwise under the elastic restoring force of the reset spring 10, the travel switch is released, the locking piece 71 moves into the slot 81 and is locked, the main coil 1 is de-energized, but due to the action of the locking piece 71 and the slot 81, the main iron core is locked in the attracted position, at this time the auxiliary coil 2 is de-energized, the auxiliary iron core 3 is in a free state and is lifted up with the lever 7;

[0025] When released, the auxiliary coil receives the command signal and quickly closes, the auxiliary iron core is pulled down, the lever rotates clockwise, the locking plate is disengaged from the slot, the main iron core is reset, and the lever 7 presses the travel switch 6 to close, so that the main coil 1 returns to the state as shown in the figure. Figure 1 The initial position shown is to prepare for the next action and run in a cycle; at this time, both the main coil and the auxiliary coil are not working.

[0026] Figure 4 It is a circuit diagram of the first embodiment of the present invention, including a DC charging circuit and an AC coil working circuit; the charging circuit includes an auxiliary coil L1 and a charging capacitor C4, and the coil working circuit includes a travel switch K1 and a main coil L2;

[0027] When the main coil L2 needs to work, the AC power supply inputs current, and the DC current is output through the rectifier circuit. The control unit starts the DC charging circuit, and the DC current quickly charges the charging capacitor through the circuit and is instantly full; another circuit supplies power to the coil working circuit of the main coil L2. At this time, the travel switch K1 is in a closed state, and the main coil L2 is energized and attracted, completing the action of attraction and locking. After the main iron core is locked by the locking plate, K1 is released and disconnected, and the coil working circuit loses power, completing the attraction and power-off holding process;

[0028] When the command circuit loses power and the main coil is released, the AC power supply is cut off, there is no voltage at the DC end, the capacitor is discharged, and power is supplied to the auxiliary coil L1, causing the auxiliary coil L1 to be activated once;

[0029] The electric energy stored in the capacitor opens Q2 through the circuit, and quickly discharges the charging capacitor C4 through the auxiliary coil L1, so that the auxiliary coil L1 is activated and attracted once, and the pulling mechanism releases the electromagnetic mechanism. When the power is lost, the circuit is quickly opened to discharge the electromagnet. The present application controls each step to act in sequence through the control circuit, and the structure is simple and compact, and the effect is good.

Claims

1. A self-locking device for an electromagnetic mechanism of an AC contactor, comprising an electromagnetic mechanism consisting of a main coil and a main iron core, characterized in that: A limit body is fixedly connected to the top of the main iron core, and the diameter of the connecting section between the limit body and the main iron core is smaller than the diameter of the limit body, forming a slot; when the main coil is energized and attracted, the limit body extends upward with the main iron core, and when the main coil is de-energized, the limit body retreats downward with the main iron core under the action of the internal reset mechanism; a mounting seat is fixedly installed on the main coil bracket, and a lever is installed above the mounting seat through a hinge shaft, and a locking plate that can swing with the lever is connected to the middle of the lever, and the locking plate is located on one side of the main iron core. When it is in the self-locking position, the locking plate can swing in the reverse direction to get into the slot to lock the main iron core. When it is in the initial position, the limit body can limit and support the locking plate, so that the lever presses a travel switch in the coil working circuit of the main coil to keep the coil working circuit conductive; one end of the lever is connected to an instantaneous driving mechanism that can instantly press the lever to swing forward, and the other end of the lever is connected to a reverse reset spring.

2. The self-locking device for the electromagnetic mechanism of an AC contactor according to claim 1, characterized in that: The instantaneous driving mechanism includes an auxiliary electromagnetic coil and an auxiliary iron core driven to extend and retract by the auxiliary electromagnetic coil, and the auxiliary iron core is connected to the lever; when the instantaneous current is passed, the instantaneous auxiliary iron core can complete a positive swinging action of pressing the lever.

3. The self-locking device for the electromagnetic mechanism of an AC contactor according to claim 1 or 2, characterized in that: The return spring is connected between the rear end of the lever and the mounting seat, and the mounting seat is also provided with a limiting surface capable of limiting the reverse swing stroke of the lever.

4. The self-locking device for the electromagnetic mechanism of the AC contactor according to claim 3, characterized in that: The instantaneous drive mechanism and the travel switch are both fixedly mounted on the mounting seat.

5. The self-locking device for the electromagnetic mechanism of an AC contactor according to claim 2, characterized in that: The upper part of the auxiliary iron core is provided with a neck with a smaller diameter, and the lever is plugged into the neck through a U-shaped slot at the end.

6. The self-locking device for the electromagnetic mechanism of an AC contactor according to any one of claims 1, 2, 4, and 5, characterized in that: The reverse return spring is a tension spring, and the travel switch is a micro switch.

7. The self-locking device for the electromagnetic mechanism of an AC contactor according to claim 6, characterized in that: The main coil has a control circuit, which includes a coil working circuit and a control circuit; the coil working circuit includes a main coil and a travel switch connected between the AC power input terminal; the control circuit includes a rectifier circuit connected to the AC power input terminal, and the control unit, auxiliary electromagnetic coil and charging capacitor are connected between the two poles of the DC output terminal of the rectifier circuit to form a DC charging and discharging circuit; the control unit can control the charging and discharging and time of the charging capacitor.

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