Magnetic circuit of magnetic latching type high-voltage direct-current contactor and contactor

Abstract

The invention provides a magnetic latching type high-voltage direct current contactor magnetic circuit which comprises an annular permanent magnet, the annular permanent magnet is arranged on the inner side between an armature and an upper yoke, the annular permanent magnet is directly attracted to the upper yoke, and the annular permanent magnet, the armature, a fixed magnetic core and a magnetic shell form a closed magnetic circuit. The invention further discloses a magnetic latching type high-voltage direct-current contactor which comprises the magnetic circuit of the magnetic latching type high-voltage direct-current contactor. The annular permanent magnet is directly adsorbed on the upper yoke and forms a closed magnetic circuit with the armature, the fixed magnetic core and the magnetic shell, middle magnetic steel or double coils are not needed, the structure is compact, the magnetic resistance is low, and the magnetic field utilization rate is high; the cost is low, only a single permanent magnet is needed, complex magnetic circuit components are omitted, and the material and processing cost is reduced; and a closed magnetic circuit is not sensitive to external electromagnetic interference, so that the circuit is suitable for high-voltage and large-current environments.

Description

Technical Field

[0001] The present invention relates to the technical field of contactors, and particularly to a magnetic circuit and a contactor of a magnetic latching high-voltage DC contactor. Background Art

[0002] Traditional high-voltage DC contactors generate a magnetic field by energizing a coil, causing the electromagnetic system to generate electromagnetic attraction. When the electromagnetic attraction is greater than the spring reaction force received by the moving iron core, the moving iron core starts to move, driving the moving contact to act, making the moving contact and the static contact touch, and the contactor enters the closed state; when the coil is de-energized, the electromagnetic attraction disappears, and under the action of the spring reaction force, the moving iron core resets, and the moving contact and the static contact separate, and the contactor is in the open state. Therefore, traditional high-voltage DC contactors need to continuously supply power to the coil when in the closed working state. On the one hand, it consumes electricity, and on the other hand, it will generate heat, affecting the performance of the product and accelerating the aging of the product.

[0003] However, the existing magnetic latching solutions have the following defects:

[0004] In the first type of solution, a middle-placed annular permanent magnet is placed between the setting coil and the reset coil, and the armature is located at the center of the middle-placed magnet. When the contactor is in the open state, the middle-placed magnet, the armature, and the yoke form a magnetic circuit to ensure the disconnection of the product. When the contactor is in the stable closed state, the middle-placed magnet, the armature, the iron core, and the magnetic conductor form a magnetic circuit to ensure the connection of the product. The connection and disconnection actions of the contactor are completed by energizing the setting coil and the reset coil. The structure of this patent is complex, and the surface magnetic intensity requirement of the middle-placed magnet is very high. Therefore, the volume of the magnet is large, and the comprehensive cost is high.

[0005] In the second type of solution, a ring-shaped permanent magnet is provided at the upper end of the coil inside the magnetic shell, a magnetic pole piece is provided between the permanent magnet and the transmission shaft, and a magnetic pole core is provided at the upper part between the coil and the iron core. The upper end of the magnetic pole core is connected to the magnetic pole piece. This structure has two magnetic paths. By applying positive and negative voltages to the coil, opposite electromagnetic forces are generated in the two magnetic paths, and the on-off of the contactor is controlled by the difference in electromagnetic forces. This solution has a complex structure, a high cost, and the electromagnetic force for maintaining the closed state of the product is small, and the anti-vibration and impact resistance is insufficient. Summary of the Invention

[0006] To solve the above problems, the present invention aims to propose a magnetic circuit and a contactor of a magnetic latching high-voltage DC contactor. By adding a ring-shaped permanent magnet inside between the armature and the upper yoke, and the ring-shaped permanent magnet is directly adsorbed on the upper yoke, without other modifications, a traditional high-voltage DC contactor can be changed into a magnetic latching high-voltage DC contactor, with low cost, simple structure, and strong vibration and impact resistance.

[0007] To achieve the above object, the technical solution of the present invention is realized as follows:

[0008] A magnetic holding type high - voltage DC contactor magnetic circuit includes an annular permanent magnet. The annular permanent magnet is arranged inside between the armature and the upper yoke. The annular permanent magnet directly adsorbs on the upper yoke and forms a closed magnetic circuit with the armature, the fixed magnetic core and the magnetic shell.

[0009] Further, in the magnetic holding state, it is maintained by the magnetic field of the annular permanent magnet, and the coil winding is only connected to positive and negative voltages at the moment of on - off.

[0010] Further, a hole for the transmission shaft to move is provided in the center of the annular permanent magnet, and the periphery is limited by the coil winding.

[0011] Further, the DC contactor adopts an encapsulation form of epoxy sealing or ceramic sealing, and the arc extinguishing cover internally contains an annular permanent magnet and contacts.

[0012] Further, there is a reaction spring between the armature and the upper yoke. The reaction spring is outside the transmission shaft. The transmission shaft and the armature are fixed together. A contact spring is installed above the transmission shaft, a moving contact is above the contact spring, and the moving contact is limited on the transmission shaft above; the upper part of the upper yoke is an arc extinguishing cover, the static contact is fixed in the arc extinguishing cover, and there is a magnetic steel inside or outside the arc extinguishing cover for arc extinguishing.

[0013] To achieve the above - mentioned purpose, the present invention also discloses a magnetic holding type high - voltage DC contactor, including the magnetic holding type high - voltage DC contactor magnetic circuit as described above.

[0014] Beneficial effects: The present invention has the following advantages: Simplified magnetic circuit and high stability: The annular permanent magnet directly adsorbs on the upper yoke, forms a closed magnetic circuit with the armature, the fixed magnetic core and the magnetic shell, without a middle - placed magnetic steel or a double - coil, with a compact structure, low magnetic resistance and high magnetic field utilization rate; Low cost: Only a single permanent magnet is required, complex magnetic circuit components are omitted, reducing material and processing costs; Strong anti - interference ability: The closed magnetic circuit is not sensitive to external electromagnetic interference and is suitable for high - voltage and large - current environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0016] Figure 1 It is a schematic structural diagram of the magnetic holding type high - voltage DC contactor magnetic circuit (epoxy sealing) according to the embodiment of the present invention;

[0017] Figure 2 It is a schematic diagram of the off - state of the magnetic holding type high - voltage DC contactor magnetic circuit (epoxy sealing) according to the embodiment of the present invention;

[0018] Figure 3Schematic diagram of the on state of the magnetic holding type high voltage DC contactor magnetic circuit (epoxy sealing) according to the embodiment of the present invention;

[0019] Figure 4 Structural schematic of the magnetic holding type high voltage DC contactor magnetic circuit (ceramic sealing) according to the embodiment of the present invention Figure 1 ;

[0020] Figure 5 Structural schematic of the magnetic holding type high voltage DC contactor magnetic circuit (ceramic sealing) according to the embodiment of the present invention Figure 2 。 Specific embodiments

[0021] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0022] The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0023] Embodiment 1

[0024] See Figures 1-3 : A magnetic holding type high voltage DC contactor magnetic circuit, including a ring permanent magnet 1, the ring permanent magnet 1 is arranged inside between the armature 2 and the upper yoke 3, the ring permanent magnet 1 directly adsorbs on the upper yoke 3, and forms a closed magnetic circuit with the armature 2, the fixed magnetic core 4, and the magnetic shell 5.

[0025] This embodiment has the following advantages:

[0026] Magnetic circuit simplification and high stability: The ring permanent magnet directly adsorbs on the upper yoke, forms a closed magnetic circuit with the armature, the fixed magnetic core, and the magnetic shell, without a middle magnetic steel or a double coil, with a compact structure, low magnetic resistance, and high magnetic field utilization rate.

[0027] Low cost: Only a single permanent magnet is required, eliminating complex magnetic circuit components and reducing material and processing costs.

[0028] Strong anti-interference ability: The closed magnetic circuit is not sensitive to external electromagnetic interference and is suitable for high voltage and large current environments.

[0029] In a specific example, in the magnetic holding state, it is maintained by the magnetic field of the ring permanent magnet 1, and the coil winding 6 is only connected to the positive and negative voltages at the moment of on and off.

[0030] This embodiment realizes zero power consumption operation: The coil is only powered on at the moment of on and off, and there is no power consumption during the long-term holding state, completely solving the heating problem caused by the continuous power supply of traditional contactors; Fast response: The magnetic circuit switching is controlled by positive and negative voltage pulses, with a short action time - in milliseconds, suitable for high-frequency operation scenarios.

[0031] In a specific example, a hole for the drive shaft 7 to move is provided in the center of the annular permanent magnet 1, and the periphery is limited by the coil winding 6.

[0032] Structural adaptability of this embodiment: The hole in the center of the permanent magnet allows the drive shaft to move freely, and the periphery is limited by the coil, which not only ensures the integrity of the magnetic circuit but also prevents the permanent magnet from shifting or falling off; High reliability: The mechanical limit design improves the anti-vibration and shock resistance performance, especially suitable for dynamic environments such as vehicle-mounted and aerospace.

[0033] In a specific example, the DC contactor adopts an epoxy seal or ceramic seal as the encapsulation form, and the arc extinguishing cover 12 internally contains the annular permanent magnet 1 and the contacts.

[0034] Environmental adaptability of this embodiment: The epoxy seal is resistant to moisture and chemical corrosion, and the ceramic seal is resistant to high temperature and arc impact, meeting the requirements of different application scenarios; Efficient arc extinguishing: The arc extinguishing cover internally contains a permanent magnet and a magnetic steel, and the arc diffusion is restricted by the magnetic field, improving the breaking capacity and service life.

[0035] In a specific example, there is a reaction spring 8 between the armature 2 and the upper yoke 3. The reaction spring 8 is outside the drive shaft 7. The drive shaft 7 and the armature 2 are fixed together. A contact spring 9 is installed above the drive shaft 7, a moving contact 10 is above the contact spring 9, and the moving contact 10 is limited on the drive shaft 7 above; The upper part of the upper yoke 3 is an arc extinguishing cover, the static contact 11 is fixed in the arc extinguishing cover, and there is a magnetic steel inside or outside the arc extinguishing cover for arc extinguishing.

[0036] This embodiment has the following advantages:

[0037] Reliable mechanical action: The linkage design of the reaction spring and the drive shaft ensures accurate reset of the armature, avoiding contact adhesion or misoperation.

[0038] Long contact life: The moving contact buffers the contact impact through the contact spring, reducing bounce wear and being suitable for frequent on-off of large currents.

[0039] Strong anti-vibration performance: The dual action of the spring and the magnetic circuit balances the external force interference, improving the stability of the high-voltage DC system.

[0040] Taking the magnetic latching epoxy high-voltage DC contactor as an example to illustrate and verify this embodiment:

[0041] The magnetic circuit in the normally open state of the magnetic latching epoxy high-voltage DC contactor is as follows Figure 2, assume that the magnetic pole directly below the permanent magnet is the N pole (it can also be the S pole, of course). When the DC contactor is in the off state, the magnetic lines of force generated by the permanent magnet form a closed loop along the armature, fixed magnetic core, magnetic shell, and upper yoke. The magnetic lines of force will magnetize the armature, and it can be considered that the surface of the armature corresponding to the permanent magnet becomes the "S pole". The armature is subjected to an upward electromagnetic suction force, but the armature is subjected to a downward reaction force from the reaction spring, and the reaction force is much greater than the electromagnetic suction force. Therefore, the armature will not move, making the vibration and shock resistance of the DC contactor in the off state relatively strong.

[0042] The on state of the magnetic latching epoxy high-voltage DC contactor is as Figure 3 : When the magnetic latching epoxy-sealed DC contactor needs to be turned on, a positive voltage is applied to the coil winding. According to the right-hand rule, the magnetic field generated by the coil will be in the same direction as the magnetic field generated by the permanent magnet. The magnetic lines of force passing through the armature will increase, and it can be considered that the surface of the armature corresponding to the permanent magnet becomes the "S pole". The armature will be subjected to an upward electromagnetic suction force. When this electromagnetic suction force is greater than the spring reaction force, the armature starts to move upward. Since the drive shaft is fixed to the armature, the drive shaft will drive the moving contact to move upward together, causing the moving contact to contact the static contact. When the armature moves to fit with the permanent magnet, it stops moving, and the moving contact and the static contact will stably contact, and the DC contactor is turned on. After being turned on, the power supply to the coil winding stops, and the magnetic lines of force of the permanent magnet will form a tight magnetic circuit closed loop along the armature, fixed magnetic core, magnetic shell, and upper yoke. There is basically no air gap in this magnetic circuit. Since the magnetic permeability of the armature, fixed magnetic core, magnetic shell, and upper yoke is relatively high, the permanent magnet will generate a relatively large electromagnetic suction force on the armature. This electromagnetic suction force is much greater than the reaction forces of the contact spring and the reaction spring on the armature at this time, and the armature will be stably attracted to the permanent magnet, and the DC contactor realizes magnetic latching and stable connection. When the magnetic latching high-voltage DC contactor needs to be turned off, only a reverse voltage needs to be applied to the coil winding. According to the right-hand rule, the magnetic field generated by the coil will be in the opposite direction to the magnetic field generated by the permanent magnet. The magnetic lines of force passing through the armature will decrease, and the electromagnetic suction force received by the armature from the permanent magnet will decrease. When the electromagnetic suction force decreases to be lower than the reaction forces of the contact spring and the reaction spring, the armature will reset downward, driving the drive shaft to move downward together, and the static contact and the moving contact will disconnect, realizing the disconnection of the contactor.

[0043] It should be noted that for the magnetic latching ceramic high-voltage DC contactor, its principle and structure are basically the same as those of the magnetic latching epoxy high-voltage DC contactor. A permanent magnet is placed above the armature, and the permanent magnet is placed at the fixed magnetic core or the upper yoke. The magnetic latching function is realized through the upper yoke, lower yoke, armature, and fixed magnetic core. Its typical structure is shown in Figures 4 and 5, but its scope not only includes the following typical structures and will not be elaborated here.

[0044] Embodiment 2

[0045] A magnetic latching high-voltage DC contactor includes the magnetic circuit of the above-mentioned magnetic latching high-voltage DC contactor.

[0046] The magnetic latching type high-voltage DC contactor of this embodiment has the same advantages as the magnetic circuit of the above-mentioned magnetic latching type high-voltage DC contactor compared with the prior art, and will not be elaborated here.

[0047] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A magnetic circuit of a magnetic latching high-voltage DC contactor, characterized in that, It includes a ring-shaped permanent magnet (1), which is arranged on the inner side between the armature (2) and the upper yoke (3). The ring-shaped permanent magnet (1) is directly adsorbed on the upper yoke (3) and forms a closed magnetic circuit with the armature (2), the fixed magnetic core (4), and the magnetic shell (5).

2. The magnetic circuit of the magnetic latching type high-voltage DC contactor according to claim 1, wherein, In the magnetic holding state, it is maintained by the magnetic field of the ring-shaped permanent magnet (1), and the coil winding (6) is only connected to positive and negative voltages instantaneously when it is turned on and off.

3. The magnetic circuit of the magnetic latching type high-voltage DC contactor according to claim 1, wherein A hole for the transmission shaft (7) to move is provided at the center of the ring-shaped permanent magnet (1), and the periphery is limited by the coil winding (6).

4. The magnetic circuit of the magnetic latching type high-voltage DC contactor according to claim 1, wherein The DC contactor adopts an encapsulation form of epoxy sealing or ceramic sealing, and the arc extinguishing cover internally contains the ring-shaped permanent magnet (1) and contacts.

5. The magnetic circuit of the magnetic latching type high-voltage DC contactor according to claim 4, wherein There is a reaction spring (8) between the armature (2) and the upper yoke (3). The reaction spring (8) is outside the transmission shaft (7). The transmission shaft (7) is fixed to the armature (2). A contact spring (9) is installed above the transmission shaft (7), and a moving contact (10) is above the contact spring (9). The moving contact (10) is limited on the transmission shaft (7) above; the upper part of the upper yoke (3) is an arc extinguishing cover, and the static contact (11) is fixed in the arc extinguishing cover. There is a magnetic steel inside or outside the arc extinguishing cover for arc extinguishing.

6. A magnetic latching high-voltage DC contactor, characterized in that, It includes the magnetic circuit of the magnetic holding type high-voltage DC contactor according to any one of claims 1-5.

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