Mechanically switchable double-coil direct current contactor

Abstract

According to the mechanically-switchable double-coil direct current contactor, in the opening position, a normally-closed switch is connected in series in a circuit loop where a suction coil is located, and the circuit loop where the coil is located is kept to be connected or disconnected; one end, facing the static contact, of the moving contact bridge assembly is provided with an insulation execution member. During closing, the pull-in coil is independently electrified or the pull-in coil and the holding coil are electrified at the same time, the movable contact bridge assembly is driven to drive the insulation execution piece to move, so that the contact system is closed, meanwhile, the insulation execution piece enables the normally-closed switch to be switched from a closed state to a disconnected state in a mechanical mode, and a circuit loop where the pull-in coil is located is disconnected; when the circuit loop where the holding coil is located is disconnected at the opening position and the circuit loop where the holding coil is located is conducted by the normally-closed switch which is converted into the disconnected state during closing; and during opening, the normally-closed switch is converted into a closed state under the action of elastic force. According to the invention, PCBs are saved, and the space utilization rate is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit protection, in particular to the technical field of direct current in circuit protection, and more particularly to a mechanically switchable double-coil direct current contactor. BACKGROUND

[0002] The double-coil direct current contactor provides an acting force for the contact system to close by the attraction coil alone or the attraction coil and the holding coil together, and provides a holding force for the contact system after closing by the holding coil. That is, the circuit loop in which the attraction coil is located needs to be disconnected after closing, and the circuit loop in which the holding coil is located needs to be kept on after closing. At present, the on and off of the attraction coil and the holding coil of the double-coil direct current contactor is controlled by switching between the coils through a PCB. The PCB structure is complex, and because it has control circuits and components, the PCB generally needs to be separated from the chamber in which the contact system is located. Because the PCB is full of circuits and components, it is easy to be disturbed by the environment or the components to fail during the operation of the direct current contactor, which leads to the failure of coil switching, thereby reducing the working reliability. Moreover, the PCB is large in size and heavy in weight, and high in processing cost, which leads to the relatively large size and weight of the double-coil direct current contactor and high cost. SUMMARY

[0003] The purpose of the present application is to provide a mechanically switchable double-coil direct current contactor, which controls the closing and opening of the attraction coil during closing and opening by mechanically cutting off the closing of the attraction coil in series with a mechanically openable and closable normally closed switch, and only provides the holding force of the contact system after closing by the holding coil. The switching between the coils is realized by a mechanical method, which improves the working reliability and anti-interference ability.

[0004] To solve the above technical problems, the technical solution provided is a mechanically switchable double-coil direct current contactor, which comprises a double-coil driving system and a contact system.

[0005] The double-coil driving system comprises an attraction coil and a holding coil arranged in parallel; a normally closed switch is connected in series in the circuit loop in which the attraction coil is located, and the circuit loop in which the attraction coil is located is on, and the circuit loop in which the holding coil is located is on or off in the open position.

[0006] The contact system comprises a moving contact bridge assembly and a stationary contact; an insulating actuator is arranged at one end of the moving contact bridge assembly facing the stationary contact; and the normally closed switch is arranged on the displacement path of the insulating actuator during closing.

[0007] When closing, the closing coil is powered alone or the closing coil and the holding coil are powered simultaneously, driving the moving contact bridge assembly to displace the insulation executing member, making the contact system close, at the same time, the insulation executing member mechanically converts the normally closed switch from the closed state to the open state, opening the circuit loop in which the closing coil is located;

[0008] When the holding coil is powered alone, the normally closed switch is converted from the open state to the closed state, and when closing, the normally closed switch converts the circuit loop in which the holding coil is located from the open state to the closed state; when opening, the normally closed switch is converted from the closed state to the open state under the action of the elastic force.

[0009] Preferably, the normally closed switch comprises a moving switch piece with elasticity, a first static switch piece and a second static switch piece arranged in an insulating manner, the first static switch piece and the second static switch piece are connected in series in the circuit loop in which the closing coil is located in an insulating manner, the moving switch piece is in conductive contact with the first static switch piece and the second static switch piece to form the normally closed switch, so that the circuit loop in which the closing coil is located at the open position is conductive; the moving switch piece is located on the displacement path of the insulation executing member; when closing, the insulation executing member drives the moving switch piece to displace to make the normally closed switch in the open state; when the circuit loop in which the holding coil is located is in the open state at the open position, when the moving switch piece is displaced to make the normally closed switch open at the closing position, the moving switch piece is in conductive contact with the disconnection of the circuit loop in which the holding coil is located, and the circuit loop in which the holding coil is located is conductive; when opening, the moving switch piece is reset under the action of the elastic force, making the normally closed switch close.

[0010] Preferably, when the circuit loop in which the holding coil is located is in the open state at the open position, a first conversion switch is arranged in the circuit loop in which the holding coil is located and the closing coil, when closing, the insulation executing member is displaced to drive the first conversion switch to open the circuit loop in which the closing coil is located, and the circuit loop in which the holding coil is located is conductive.

[0011] Preferably, the first switch includes the normally closed switch and a third static switch piece; the normally closed switch includes a conductive and elastic moving switch piece, and an insulatively spaced first static switch piece and a second static switch piece, the insulatively spaced first static switch piece and the second static switch piece are connected in series in a circuit loop where the attract coil is located, in the open position, the moving switch piece is in conductive contact with the first static switch piece and the second static switch piece to form the normally closed switch; one end of the holding coil is in conductive connection with the first static switch piece, and the other end is in conductive connection with the third static switch piece; one end of the moving switch piece is fixedly connected with the first static switch piece, and the other end is overlapped on the second static switch piece, and the third static switch piece is located on the displacement path of the moving switch piece; when the switch is closed, the insulating actuator drives the moving switch piece to disengage from the second static switch piece, and then the moving switch piece is in conductive contact with the third static switch piece to conduct the circuit loop where the holding coil is located.

[0012] Preferably, the double-coil DC contactor is provided with two auxiliary contacts insulatively spaced at one end of the static contact, and the two auxiliary contacts are connected in series in an auxiliary circuit in an insulatively spaced manner; the insulating actuator is provided with an auxiliary contact spring corresponding to the auxiliary contact; when the switch is closed, the insulating actuator is displaced to convert the normally closed switch from the closed state to the open state, and at the same time, the auxiliary contact spring is in conductive contact with the auxiliary contact to conduct the auxiliary circuit where the auxiliary contact is located.

[0013] Preferably, the auxiliary contact and the normally closed switch are respectively arranged on opposite sides of the two static contact wires.

[0014] Preferably, the auxiliary contact spring and the insulating actuator are integrally injection molded.

[0015] Preferably, the double-coil DC contactor is provided with two auxiliary contacts insulatively spaced at one end of the static contact, and the two auxiliary contacts are connected in series in an auxiliary circuit in an insulatively spaced manner; when the switch is in the open position, the circuit where the holding coil is located is conducted, and a second switch is arranged between the circuit loop where the attract coil is located and the auxiliary circuit where the auxiliary contact is located, in the open position, the second switch conducts the circuit loop where the attract coil is located and disconnects the auxiliary circuit where the auxiliary contact is located; when the switch is closed, the insulating actuator is displaced to drive the second switch to disconnect the circuit loop where the attract coil is located and conduct the auxiliary circuit where the auxiliary contact is located.

[0016] Preferably, the second conversion switch comprises the normally closed switch and two auxiliary contacts, the normally closed switch comprises a conductive moving contact and insulatively spaced first and second stationary contacts, the moving contact is pressed on the first and second stationary contacts by an elastic member to form the normally closed switch; the two auxiliary contacts are located on the moving contact displacement path and are located on opposite sides of the moving contact displacement direction with the first and second stationary contacts respectively; when the insulating actuator drives the moving contact to displace to make the normally closed switch switch from the closed state to the open state, at the same time, the moving contact is driven to be in conductive contact with the auxiliary contacts to make the auxiliary circuit in which the auxiliary contacts are located conductive.

[0017] Preferably, the elastic member is a spring, one end of the elastic member is fixed, and the other end is fixedly connected with the moving contact.

[0018] The double-coil DC contactor capable of mechanical switching of the application adopts a mechanically structured normally closed switch in series in the attraction coil, an insulating actuator is arranged on the moving contact bridge assembly, the normally closed switch is opened by displacement of the insulating actuator, and the normally closed switch is closed by elasticity of the moving contact, thereby realizing mechanical switching of the circuit loop in which the attraction coil is located, saving the PCB circuit board for switching control of the coil, and improving switching reliability and anti-interference ability by replacing the PCB with a mechanical structure.

[0019] The mechanically structured normally closed switch cooperates with the stationary contact in series in the circuit loop in which the holding coil is located to form a first conversion switch, under driving of displacement of the insulating actuator and elastic force of the moving contact, switching between the circuit loop in which the attraction coil is located and the circuit loop in which the holding coil is located is realized when the contact is opened and closed, the circuit loop in which the attraction coil is located is made conductive and the circuit loop in which the holding coil is located is made non-conductive when the contact is opened, and the circuit loop in which the attraction coil is located is made non-conductive and the circuit loop in which the holding coil is located is made conductive when the contact is closed.

[0020] The mechanically structured normally closed switch cooperates with the auxiliary contact in series in the circuit loop in which the auxiliary contact is located to form a second conversion switch, under driving of displacement of the insulating actuator and elastic force of the moving contact, switching between the auxiliary circuit in which the attraction coil is located and the auxiliary circuit in which the auxiliary contact is located is realized when the contact is opened and closed, the circuit loop in which the attraction coil is located is made conductive and the auxiliary circuit in which the auxiliary contact is located is made non-conductive when the contact is opened, and the circuit loop in which the attraction coil is located is made non-conductive and the auxiliary circuit in which the auxiliary contact is located is made conductive when the contact is closed.

[0021] The elastic force of the moving contact can be the elastic force of the moving contact itself or the elastic force of an elastic member fixedly connected with the moving contact.

[0022] By connecting normally closed switches in series, PCB circuit boards are saved, and space in existing DC contactors is fully utilized, improving space utilization. Due to the reduction in PCB circuit boards, the normally closed switches are very lightweight and compact. The insulating actuators are injection molded, resulting in relatively low weight. Therefore, compared to existing DC contactors, the weight of the DC contactor is reduced.

[0023] At the same time, by saving PCB circuit boards and the space required for their installation, the overall structure and assembly are simplified. Attached Figure Description

[0024] Figure 1 It is a circuit diagram of two coils connected in parallel and both conducting, with a normally closed switch connected in series in the coil to pull in the coil.

[0025] Figure 2 yes Figure 1 A detailed structural diagram.

[0026] Figure 3 This is a schematic diagram of a normally closed switch.

[0027] Figure 4 This is a circuit diagram showing the first switching switch for the pull-in coil and the holding coil.

[0028] Figure 5 yes Figure 4 A detailed structural diagram.

[0029] Figure 6 This is a schematic diagram showing the structure in which auxiliary contacts and normally closed switches are respectively located on both sides inside the protective cover.

[0030] Figure 7 yes Figure 1 Based on the principle, a circuit diagram showing the circuit principle of setting a second changeover switch between the circuit loop where the energizing coil is located and the auxiliary circuit where the auxiliary contacts are located.

[0031] Figure 8 yes Figure 7 A detailed structural diagram.

[0032] Figure 9 yes Figure 8 A schematic diagram of the second changeover switch structure.

[0033] Figure Labels

[0034] 1. Pull-in coil; 2. Holding coil; 3. Normally closed switch; 5. Protective cover; 6. Moving contact bridge assembly; 7. Double coil; 8. Moving iron core; 9. Push rod; 10. First stationary switch piece; 11. Second stationary switch piece; 12. Moving switch piece; 101. First lead wire; 102. Second lead wire; 15. Insulating actuator; 16. Auxiliary contact spring; 20. First changeover switch; 21. Third stationary switch piece; 22. Auxiliary contact; 23. Stationary contact; 24. Second changeover switch; 25. Elastic element; 26. Auxiliary circuit. Detailed Implementation

[0035] The mechanically switchable dual-coil DC contactor of the present invention includes a dual-coil drive system and a contact system;

[0036] The dual-coil drive system includes a pull-in coil and a holding coil arranged in parallel; a normally closed switch is connected in series in the circuit where the pull-in coil is located. When the switch is open, the circuit where the pull-in coil is located is closed, and the circuit where the holding coil is located is either closed or open.

[0037] The contact system includes a moving contact bridge assembly and a stationary contact; an insulating actuator is provided at the end of the moving contact bridge assembly facing the stationary contact; the normally closed switch is located on the displacement path of the insulating actuator when the switch is closed;

[0038] When closing, the energizing coil is energized alone or the energizing coil and the holding coil are energized simultaneously, driving the moving contact bridge assembly to move the insulating actuator, causing the contact system to close. At the same time, the insulating actuator mechanically changes the normally closed switch from the closed state to the open state, disconnecting the circuit loop where the energizing coil is located.

[0039] When the circuit is open, the circuit containing the holding coil is disconnected. When the circuit is closed, the normally closed switch, which is in the open state, connects the circuit containing the holding coil. When the circuit is open, the normally closed switch is converted to the closed state by the spring force.

[0040] The following describes preferred embodiments in detail with reference to the accompanying drawings. The directional terms used are for reference only and do not constitute a limitation on the technical solution of this invention.

[0041] The schematic diagram of the mechanically switchable dual-coil DC contactor of the present invention is shown below. Figure 1The pull-in coil 1 and the holding coil 2 are electrically connected to the power supply, forming a parallel connection. The circuit containing the holding coil 2 is in a conductive state. A normally closed switch 3 is connected in series with the pull-in coil 1, controlling the conduction or disconnection of the circuit containing the pull-in coil 1. In the open position, both the circuits containing the pull-in coil 1 and the holding coil 2 are conductive. An insulating actuator is installed on the moving contact bridge assembly. When closing, the moving contact bridge assembly moves towards the stationary contact. Simultaneously with closing, the insulating actuator on the moving contact bridge assembly mechanically opens the normally closed switch 3, disconnecting the circuit containing the pull-in coil 1, leaving only the holding coil 2 energized to continue working, providing holding force for the contact system after closing.

[0042] For details on the implementation structure, please refer to [link / see details]. Figure 2 and Figure 3 It includes a dual-coil drive system, a contact system, and a protective cover 5. The dual-coil drive system and the contact system are located in different chambers, and the protective cover 5 is installed in the chamber where the contact system is located. The contact system includes a moving contact bridge assembly 6 and a stationary contact 23. The moving contact bridge assembly 6 is installed in the protective cover 5, and the stationary contact is fixedly installed on the top of the protective cover 5. One end of the stationary contact is located in the protective cover 5, and the other end is located outside the protective cover 5 and can be connected to the external circuit of the contactor.

[0043] The dual-coil drive system includes dual coils 7, a moving iron core 8, and a push rod 9. The push rod 9 is fixed to the moving iron core 8, and one end of the push rod 9 is located in the chamber containing the contact system. The moving contact bridge assembly 6 is mounted on one end of the push rod 9 located in the chamber containing the contact system. The dual coils 7 include a pull-in coil 1 and a holding coil 2. The two ends of the pull-in coil 1 are led out through a conductive first lead 101 and a second lead 102. A conductive first stationary switch piece 10 and a second stationary switch piece 11, which are insulated from each other, and two auxiliary contacts (not shown) are fixed on the top of the protective cover 5. The first stationary switch piece 10 and the second stationary switch piece 11 pass through the protective cover 5 and are sealed to the contact surface of the protective cover 5. One end of the first stationary switch piece 10 and the second stationary switch piece 11 is located inside the protective cover 5, and the other end is located on the top outer side of the protective cover 5. The first lead 101 and the second lead 102 are conductively connected to one end of the first stationary switch piece 10 and the second stationary switch piece 11 located on the top outer side of the protective cover 5, respectively. The first stationary switch piece 10 and the second stationary switch piece 11, located inside the protective cover 5, have one end bent into an L-shape. One end of the moving switch piece 12 is fixedly connected to the bottom of the first stationary switch piece 10 inside the protective cover 5, while the other end of the moving switch piece 12 is a free end, overlapping the L-shape of the second stationary switch piece 11. The first stationary switch piece 10, the second stationary switch piece 11, and the moving switch piece 12 form a normally closed switch 3 that is mechanically closed. All three pieces—the first stationary switch piece 10, the second stationary switch piece 11, and the moving switch piece 12—are conductive spring structures with a certain degree of elasticity. This connection method allows the moving switch piece 12 to undergo a certain elastic deformation when it overlaps the second stationary switch piece 11. The elastic force presses one end of the moving switch piece 12 firmly against the second stationary switch piece 11, ensuring reliable contact. The positions of the first stationary switch piece 10 and the second stationary switch piece 11 are designed to avoid affecting the movement of the moving contact bridge assembly for closing and the conduction of auxiliary contacts. The normally closed switch 3, formed by the first stationary switch piece 10, the second stationary switch piece 11, and the moving switch piece 12, is connected in series in the circuit loop containing the coil 1. Two auxiliary contacts 22, spaced apart by insulation, are connected in series in the auxiliary circuit 26. In the open position, the two insulatingly spaced auxiliary contacts disconnect the auxiliary circuit. The auxiliary circuit provides indication for the opening and closing of the DC contactor.

[0044] An insulating actuator 15 is fixedly mounted on one end of the moving contact bridge assembly 6 facing the stationary contact. The insulating actuator 15 protrudes from the end of the moving contact bridge assembly 6 and is positioned corresponding to the moving switch piece 12. An auxiliary contact spring 16 is mounted on the insulating actuator 15, corresponding to the auxiliary contact. The auxiliary contact spring 16 is offset from the first stationary switch piece 10, the second stationary switch piece 11, and the moving switch piece 12; that is, the displacement of the auxiliary contact spring 16 will not affect the operation of the normally closed switch 3. The insulating actuator 15 is made of insulating material and is injection molded. To simplify the structure, the insulating actuator and the auxiliary contact spring 16 are integrally injection molded.

[0045] Workflow:

[0046] When the contactor closes, the power is turned on. The energizing coil 1 and the closing coil 2 work together to move the moving iron core 8, along with the push rod 9, the moving contact bridge assembly 6, and the insulating actuator 15, towards the stationary contact. The moving contact bridge assembly 6 contacts the stationary contact to close the circuit. Then, the insulating actuator 15 pushes the end of the moving switch piece 12 that is attached to the second stationary switch piece 11 to move away from the second stationary switch piece 11, thus disconnecting the first stationary switch piece 10 and the second stationary switch piece 11. That is, the normally closed switch 3 is opened, de-energizing the energizing coil 1, leaving only the holding coil 2 energized to provide holding force for the contact system after closing. At the same time, after the normally closed switch 3 is opened, the auxiliary contact spring 16 makes conductive contact with the auxiliary contact, making the auxiliary contact conductive.

[0047] When the circuit is opened, the power is turned off, and the moving contact bridge assembly 6, along with the insulating actuator 15 and the auxiliary contact spring 16, moves away from the stationary contact. Under the action of the spring, the moving switch piece 12 re-attaches to the second stationary switch piece 11, causing the normally closed switch 3 to close.

[0048] By adding an insulating actuator and a normally closed switch, the normally closed switch 3 is mechanically disconnected when the moving contact bridge assembly shifts, achieving automatic switching between the two coils. This avoids the need for a PCB board in the contactor, reducing production costs. The mechanically installed normally closed switch 3 replaces the PCB board for automatic disconnection between the two coils, improving operational reliability and anti-interference capabilities. Simultaneously, the first stationary switch piece, second stationary switch piece, moving switch piece, and insulating actuator are all housed within the existing space of the contactor, making full use of previously unused space and improving space utilization. The absence of the first stationary switch piece, second stationary switch piece, moving switch piece, and insulating actuator results in a smaller size and lighter weight, reducing the overall weight of the contactor compared to incorporating a PCB board.

[0049] exist Figure 1 and Figure 2In the open position, the circuit containing the energizing coil 1 and the circuit containing the holding coil 2 are connected in parallel, and the holding switch 3 is connected in series in the circuit containing the energizing coil 1. When closing, both the energizing coil 1 and the holding coil 2 are energized, acting together on the moving iron core to provide a closing force. In other embodiments, when closing, the energizing coil 1 is energized to provide a closing force, and after closing, the holding coil 2 is energized to provide a holding force to the contact system. See the circuit diagram below. Figure 4 A first changeover switch 20 is installed in both the circuit containing the coil 1 and the circuit containing the coil 2. The first changeover switch 20 switches between on and off states for the circuits containing the coil 1 and the coil 2. In the open position, the first changeover switch 20 connects the circuit containing the coil 1 and disconnects the circuit containing the coil 2. In the closed position, after the moving contact bridge and stationary contact of the moving contact bridge assembly 6 make conductive contact, the first changeover switch 20, driven by the insulating actuator 15, mechanically changes its state, disconnecting the circuit containing the coil 1 and connecting the circuit containing the coil 2. The coil 2 then provides holding force to the contact system after the circuit is closed.

[0050] For details, please refer to the structure. Figure 5 ,exist Figure 2 Based on the existing structure, a conductive third stationary switch piece 21 is added. The third stationary switch piece 21 is fixedly mounted on the top of the protective cover 5, corresponding to the moving switch piece 12. One end of the third stationary switch piece 21 is located outside the top of the protective cover 5, and the other end is located inside the protective cover 5, on the displacement path of the moving switch piece 12, which is no longer in contact with the second stationary switch piece 11 and is away from the second stationary switch piece 11. One end of the holding coil 2 is conductively connected to the first stationary switch piece 10 through a lead wire, and the other end is conductively connected to the third stationary switch piece 21 through a lead wire. The holding coil 2 is connected to the power supply through the lead wire, the first stationary switch piece 10, and the third stationary switch piece 21 to form a circuit loop. In the open position, the first stationary switch piece 10 and the third stationary switch piece 21, which are set with an insulating gap, disconnect the circuit loop where the holding coil 2 is located, and the moving switch piece 12 and the third stationary switch piece 21 maintain an insulating gap distance. The normally closed switch 3, formed by the first stationary switch piece 10, the second stationary switch piece 11, and the moving switch piece 12, combined with the third stationary switch piece 21, forms the first changeover switch 20, which controls the switching between the conduction and disconnection of the circuit loop containing the coil 1 and the holding coil 2.

[0051] Workflow:

[0052] When the circuit is closed, the moving switch piece 12 connects to the second stationary switch piece 11, opening the circuit between the closed coil 1 and the power supply. When the power supply is turned on, the closed coil 1 is energized, and the moving contact bridge assembly and the insulating actuator move together. The moving contact bridge assembly closes with the stationary contact. Then, the insulating actuator 15 drives the moving switch piece 12 to disengage from the second stationary switch piece 11 and make conductive contact with the third stationary switch piece 21, opening the circuit between the holding coil 2 and the power supply. The holding coil 2 provides holding force for the contact system to close. At the same time, the auxiliary contact spring piece 16 opens the auxiliary contact.

[0053] When the circuit breaker is tripped, the power is turned off. The moving contact bridge assembly 6, the insulating actuator 15, and the auxiliary contact spring 16 move away from the stationary contact. The moving switch piece 12 disengages from the insulating actuator 15. Under the action of the spring, the moving switch piece 12 disengages from the conductive contact with the third stationary switch piece 21 and reconnects to the second stationary switch piece 11.

[0054] By adding a third stationary switch piece 21, the normally closed switch 3 is changed into a first changeover switch 20, allowing the pull-in coil 1 and the holding coil 2 to work independently.

[0055] exist Figure 2 Based on this, see Figure 6 The normally closed switch 3, formed by the first stationary switch piece 10, the moving switch piece 12, and the second stationary switch piece 11, and the auxiliary contact 22 are respectively disposed on both sides inside the ceramic cover, that is, on opposite sides of the line connecting the two stationary contacts 23. The insulating actuator 15 and the moving contact bridge are disposed in a cross manner on the moving contact bridge assembly 6, with both ends of the insulating actuator 15 located on both sides of the moving contact bridge assembly 6. One end of the insulating actuator 15 is used to drive the moving switch piece to open the normally closed switch 3, and the other end is provided with an auxiliary contact spring 16 for conducting the two auxiliary contacts 22. The purpose of this arrangement is to make full use of the space inside the protective cover 5. The insulating actuator 15 and the moving contact bridge are preferably disposed in a cross manner.

[0056] exist Figure 1 Based on this, see Figure 7 The auxiliary circuit 26 containing the auxiliary contact and the circuit circuit containing the coil 1 are switched between the auxiliary circuit 26 and the circuit circuit containing the coil 2 via a double-break second changeover switch 24. The circuit circuits containing the coil 1 and the holding coil 2 are connected in parallel and are both conductive in the open position. The second changeover switch 24 is installed at the circuit circuit containing the coil 1 and the auxiliary circuit 26 containing the auxiliary contact. In the open position, the second changeover switch 24 connects the circuit circuit containing the coil 1 and disconnects the auxiliary circuit 26. After closing, the second changeover switch 24 disconnects the circuit circuit containing the coil 1 and connects the auxiliary circuit 26.

[0057] For details, please refer to the structure. Figure 8 andFigure 9 Two auxiliary contacts 22 are connected in series in the auxiliary circuit 26 with an insulating gap. A movable switch 12 is provided between the first stationary switch piece 10 and the second stationary switch piece 11 in the circuit loop where the two auxiliary contacts 22 are located and the circuit loop where the coil 1 is located. The switching between the auxiliary circuit and the circuit loop where the coil 1 is located is realized by the displacement of the movable switch piece 12 between the auxiliary contacts 22 and the first stationary switch piece 10 and the second stationary switch piece 11. That is, the switching between the circuit loop where the coil 1 is located and the auxiliary circuit where the auxiliary contacts are located is realized by the combination of the first stationary switch piece 10, the second stationary switch piece 11, and the movable switch piece 12 with the two auxiliary contacts 22 to form a second changeover switch 24.

[0058] An insulating actuator 15 is disposed on the moving contact bridge assembly 6. The two ends of the moving switch piece 12 are respectively mounted on one end of the L-shaped bend of the first stationary switch piece 10 and the second stationary switch piece 11. An elastic element 25 is disposed between the moving switch piece 12 and the top of the protective cover 5. One end of the elastic element 25 is fixedly connected to the top of the protective cover 5, and the other end is fixedly connected to the moving switch piece 12. In this embodiment, the elastic element 25 is a spring. Two auxiliary contacts 22 are fixedly disposed on the top of the protective cover 5 with an insulating gap. One end of each auxiliary contact 22 is located inside the protective cover 5, and the other end is electrically connected to the auxiliary circuit. The two auxiliary contacts 22 located inside the protective cover 5 are positioned corresponding to the moving switch piece 12, between the moving switch piece 12 and the top of the protective cover 5, and along the displacement path of the moving switch piece 12. The normally closed switch formed by the first stationary switch piece 10, the second stationary switch piece 11, the moving switch piece 12, and the elastic element 25, combined with the two auxiliary contacts 22, forms the second changeover switch 24. When the circuit is open, the elastic force of the elastic element 25 presses both ends of the moving switch piece 12 against the first stationary switch piece 10 and the second stationary switch piece 11, so that the circuit where the coil 1 is located is connected; and the auxiliary contact 22 maintains an insulating distance from the moving switch piece 12, so that the auxiliary circuit is not connected.

[0059] Working principle:

[0060] When the circuit is closed, the power is turned on, and the circuit circuit containing the energizing coil 1 and the holding coil 2 is energized. Under the combined force of the energizing coil 1 and the holding coil 2, the moving iron core 8, along with the push rod 9, the moving contact bridge assembly 6, and the insulating actuator 15, moves toward the stationary contact. The moving contact bridge makes conductive contact with the stationary contact to close the circuit. At the same time, the insulating actuator 15 pushes the moving switch piece 12 toward the auxiliary contact 22, causing the moving switch piece 12 to disengage from the conductive contact with the first stationary switch piece 10 and the second stationary switch piece 11, thus disconnecting the circuit circuit containing the energizing coil 1. Only the holding coil 2 continues to be energized and works. Simultaneously, the moving switch piece 12 moves to make conductive contact with the two auxiliary contacts 22, making the auxiliary circuit conductive and realizing the switching between the circuit containing the energizing coil 1 and the auxiliary circuit.

[0061] When the circuit breaker is tripped, the power supply is disconnected. The moving contact bridge assembly, along with the insulating actuator 15, moves away from the stationary contact. The moving switch piece 12 loses the contact of the insulating actuator 15 and is driven to move under the elastic force of the elastic member 25. This causes the moving switch piece 12 to re-make conductive contact with the first stationary switch piece 10 and the second stationary switch piece 11, thus connecting the circuit loop where the coil 1 is located.

[0062] By saving auxiliary contact springs, the auxiliary contacts and normally closed switches are highly integrated. Through a single moving switch with a double-break structure, a single switch can serve two purposes: switching between coil engagement and coil holding, and providing auxiliary contact functionality. This greatly improves the space utilization within the cavity where the contact system is located, making the contactor structure more compact, simple, and reliable.

Claims

1. A mechanically switchable dual-coil DC contactor, characterized by, The application relates to a double-coil driving system and a contact system. The double-coil driving system comprises an attraction coil and a holding coil arranged in parallel; a normally closed switch is arranged in series in the circuit loop of the attraction coil; when the switch is in the open position, the circuit loop of the attraction coil is turned on, and the circuit loop of the holding coil is turned on or off. The contact system comprises a movable contact bridge assembly and a static contact; an insulation actuator is arranged at one end of the movable contact bridge assembly towards the static contact; the normally closed switch is arranged on the displacement path of the insulation actuator when the switch is in the closed position. When the switch is in the closed position, the attraction coil is powered alone or the attraction coil and the holding coil are powered simultaneously to drive the movable contact bridge assembly to displace the insulation actuator, so that the contact system is closed; meanwhile, the insulation actuator mechanically drives the normally closed switch to switch from the closed state to the open state, and the circuit loop of the attraction coil is disconnected. When the circuit loop of the holding coil is disconnected in the open position, the normally closed switch in the closed state is turned on to connect the circuit loop of the holding coil when the switch is in the closed position; when the switch is in the open position, the normally closed switch is switched to the closed state under the action of the elastic force.

2. The dual-coil DC contactor of claim 1, wherein, The normally closed switch comprises a movable switch piece with elasticity, a first static switch piece and a second static switch piece arranged in insulation, the first static switch piece and the second static switch piece are arranged in series in the circuit loop of the attraction coil in an insulation manner, the movable switch piece is in conductive contact with the first static switch piece and the second static switch piece to form the normally closed switch, so that the circuit loop of the attraction coil in the open position is turned on; the movable switch piece is arranged on the displacement path of the insulation actuator; when the switch is in the closed position, the insulation actuator drives the movable switch piece to displace to make the normally closed switch in the open state; when the circuit loop of the holding coil is disconnected in the open position, when the movable switch piece is displaced to disconnect the normally closed switch in the closed position, the movable switch piece is in conductive contact with the circuit loop of the holding coil in the open position to connect the circuit loop of the holding coil; when the switch is in the open position, the movable switch piece is reset under the action of the elastic force to make the normally closed switch in the closed state.

3. The dual-coil DC contactor of claim 2, wherein, When the circuit loop of the holding coil is disconnected in the open position, a first switch is arranged in the circuit loop of the attraction coil and the circuit loop of the holding coil; when the switch is in the closed position, the insulation actuator is displaced to drive the first switch to disconnect the circuit loop of the attraction coil and connect the circuit loop of the holding coil.

4. The dual-coil DC contactor of claim 3, wherein, The first switch includes the normally closed switch and a third static switch piece; the normally closed switch includes a conductive and elastic moving switch piece, and an insulatively spaced first static switch piece and a second static switch piece, the insulatively spaced first static switch piece and the second static switch piece are connected in series in a circuit loop where the attracting coil is located, in the open position, the moving switch piece is in conductive contact with the first static switch piece and the second static switch piece to form the normally closed switch; one end of the holding coil is in conductive connection with the first static switch piece, and the other end is in conductive connection with the third static switch piece; one end of the moving switch piece is fixedly connected with the first static switch piece, and the other end is overlapped on the second static switch piece, and the third static switch piece is located on the displacement path of the moving switch piece; when the switch is closed, the insulating actuator drives the moving switch piece to displace and disengage from the second static switch piece, and the moving switch piece is in conductive contact with the third static switch piece to conduct the circuit loop where the holding coil is located.

5. The dual-coil DC contactor according to any one of claims 1 to 4, characterized in that, In the double-coil DC contactor, one end of the static contact is provided with two auxiliary contacts which are insulatively spaced and connected in series in an auxiliary circuit; the insulating actuator is provided with auxiliary contact springs corresponding to the auxiliary contacts; when the switch is closed, the insulating actuator is displaced to convert the normally closed switch from the closed state to the open state, and at the same time, the auxiliary contact springs are in conductive contact with the auxiliary contacts to conduct the auxiliary circuit where the auxiliary contacts are located.

6. The dual-coil DC contactor of claim 5, wherein, The auxiliary contacts and the normally closed switch are respectively arranged on opposite sides of the two static contact wires.

7. The dual-coil DC contactor of claim 5, wherein, The auxiliary contact springs and the insulating actuator are integrally injection molded.

8. The dual-coil DC contactor of claim 1, wherein, In the double-coil DC contactor, one end of the static contact is provided with two auxiliary contacts which are insulatively spaced and connected in series in an auxiliary circuit; when the switch is in the open position, the circuit where the holding coil is located is conducted, and a second switch is arranged between the circuit loop where the attracting coil is located and the auxiliary circuit where the auxiliary contacts are located, in the open position, the second switch conducts the circuit loop where the attracting coil is located and disconnects the auxiliary circuit where the auxiliary contacts are located; when the switch is closed, the insulating actuator is displaced to drive the second switch to disconnect the circuit loop where the attracting coil is located and conduct the auxiliary circuit where the auxiliary contacts are located.

9. The dual-coil DC contactor of claim 8, wherein, The second change-over switch comprises the normally closed switch and two auxiliary contacts, the normally closed switch comprises a conductive moving contact and insulatively spaced first and second stationary contacts, the moving contact is pressed on the first and second stationary contacts by an elastic member to form the normally closed switch; the two auxiliary contacts are located on the displacement path of the moving contact and are respectively located on the opposite sides of the moving contact in the displacement direction of the moving contact; when the insulating actuator drives the moving contact to displace to change the normally closed switch from the closed state to the open state, the moving contact is driven to conductively contact the auxiliary contacts to make the auxiliary circuit in which the auxiliary contacts are located conductive.

10. The dual-coil DC contactor of claim 9, wherein, The elastic member is a spring, one end of the elastic member is fixed, and the other end is fixedly connected with the moving contact.

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