Electromagnetic mechanism for switching device and switching device

Abstract

The invention relates to the technical field of switching devices, and provides an electromagnetic mechanism for a switching device, which comprises a movable iron core assembly capable of being driven by a coil body assembly, and is characterized in that the movable iron core assembly comprises a transmission rod, an over-travel spring sleeved outside the transmission rod and a movable iron core sleeved outside the over-travel spring; the transmission rod is provided with a first step abutting against one end of the overtravel spring, and the coil body assembly drives the movable iron core to drive the transmission rod to move linearly after being electrified. The invention further provides a switching device which comprises the electromagnetic mechanism. According to the invention, the matching effect of the characteristics of the disc spring and the force value of the over-travel spring is utilized, the influence of the impact force on the bounce of the contacts when the moving and static contacts of the switching device are contacted is reduced, the pre-pressure of the contacts of the movable iron core assembly can be adjusted by adjusting the number of the adjusting washers in the assembly process, and the over-travel spring is designed in the movable iron core assembly, so that the assembly efficiency is improved. And the pre-pressure value and the final pressure value between the contacts can be indirectly adjusted and ensured when the switch is closed.

Description

Technical Field

[0001] The present invention relates to the technical field of switch electrical appliances, and in particular to an electromagnetic mechanism for a switch electrical appliance and the switch electrical appliance. Background Art

[0002] In existing technology, DC switchgear often uses electromagnetic mechanisms to provide the closing force. These mechanisms generate the required electromagnetic force by regulating the voltage or current to control the magnetic field strength. Their magnetic field forms and disappears quickly, and their simple structure facilitates production and maintenance, making them suitable for applications requiring rapid operation. However, existing switchgear suffer from poor pull-in voltage consistency, large closing bounce, severe wear and even jamming of moving parts, and significant electromagnetic force divergence and attenuation, all of which affect their reliability. Summary of the Invention

[0003] The object of the present invention is to provide an electromagnetic mechanism for a switching electrical appliance and a switching electrical appliance, which can at least solve some of the defects in the prior art.

[0004] To achieve the above-mentioned purpose, an embodiment of the present invention provides the following technical solution: an electromagnetic mechanism for a switching electrical appliance, comprising a moving iron core assembly that can be driven by a coil body assembly, characterized in that: the moving iron core assembly includes a transmission rod, an overtravel spring sleeved outside the transmission rod, and a moving iron core sleeved outside the overtravel spring, the transmission rod has a first step abutting against one end of the overtravel spring, and after the coil body assembly is energized, it drives the moving iron core to drive the transmission rod to move linearly.

[0005] Furthermore, the moving iron core assembly also includes a disc spring and an adjustment washer mounted on the transmission rod, the transmission rod has a second step abutting the disc spring, the adjustment washer is located between the disc spring and the second step, there is a preload washer between the adjustment washer and the second step, and there is a gap between the second step and the preload washer.

[0006] Furthermore, the coil body assembly includes a coil skeleton and a coil body wound on the coil skeleton, the transmission rod passes through the coil skeleton, and the moving iron core at least partially extends into the coil skeleton.

[0007] Furthermore, the coil body assembly further includes a lead end insert, which is embedded in the coil frame and has a welding groove and a threaded hole.

[0008] Furthermore, it also includes an upper magnetic yoke assembly and an outer magnetic yoke assembly, the coil body assembly is arranged in the outer magnetic yoke assembly, and the upper magnetic yoke is installed on the outer magnetic yoke assembly.

[0009] Furthermore, the upper yoke assembly includes an upper end cover and an inner yoke, the upper end cover is mounted on the outer yoke assembly, the inner yoke extends into the coil body assembly, and the inner yoke has a first opening for the transmission rod to extend into, and a first bushing for lubrication and guidance is provided on the wall of the first opening.

[0010] Furthermore, an exhaust hole is provided on the inner magnetic yoke.

[0011] Furthermore, the outer magnetic yoke assembly includes an outer magnetic yoke with an inner cavity and a lower end cover arranged at the lower end of the outer magnetic yoke, the lower end cover has a second opening for the transmission rod to extend into, and a second bushing for lubrication and guidance is provided on the hole wall of the second opening.

[0012] Furthermore, it also includes a limiting seat for fixing the upper magnetic yoke assembly on the outer magnetic yoke assembly, and the transmission rod is also sleeved with a reset spring, and the reset spring is located in the upper magnetic yoke assembly.

[0013] An embodiment of the present invention provides another technical solution: a switching electrical device including the electromagnetic mechanism described above.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. The overtravel spring is designed into the moving iron core assembly to facilitate indirect adjustment and ensure the pre-pressure value and final pressure value between the contacts when the switch is closed.

[0016] 2. By utilizing the force matching effect of the disc spring characteristics and the overtravel spring, the impact of the impact force on the contact bounce when the moving and static contacts of the switch electrical appliance come into contact is reduced. At the same time, the contact pre-pressure of the moving iron core assembly can be adjusted by adjusting the number of adjustment washers during the assembly process.

[0017] 3. The bushing used for lubrication guide ensures the stability of the electromagnetic attraction of the moving iron core in the electromagnetic mechanism.

[0018] 4. After assembly, the mechanism can be tested for performance as a whole, which is convenient for inspection before assembly of the whole machine and replacement and maintenance during subsequent product operation.

[0019] 5. The parts are rough-machined first, then welded, and then fine-machined, which ensures the assembly accuracy of the parts and improves the stability of the electromagnetic mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A cross-sectional view of the structure of an electromagnetic mechanism for a switching electrical appliance provided by an embodiment of the present invention;

[0021] Figure 2 A schematic structural diagram of an electromagnetic mechanism for a switching electrical appliance provided by an embodiment of the present invention;

[0022] Figure 3 A structural cross-sectional view of an upper magnetic yoke assembly of an electromagnetic mechanism for a switching electrical appliance provided by an embodiment of the present invention;

[0023] Figure 4 A schematic structural diagram of an outer yoke assembly of an electromagnetic mechanism for a switching electrical appliance provided by an embodiment of the present invention;

[0024] Figure 5 A structural cross-sectional view of a coil body assembly of an electromagnetic mechanism for a switching electrical appliance provided by an embodiment of the present invention;

[0025] Figure 6 A schematic structural diagram of a lead terminal insert for an electromagnetic mechanism of a switching electrical appliance provided by an embodiment of the present invention;

[0026] Figure 7 A structural cross-sectional view of a moving iron core assembly of an electromagnetic mechanism for a switching device provided by an embodiment of the present invention;

[0027] Figure 8 A schematic structural diagram of a transmission rod of an electromagnetic mechanism for a switching electrical appliance provided by an embodiment of the present invention;

[0028] Figure 9 A cross-sectional view of the structure of an electromagnetic mechanism for a switching electrical appliance provided by an embodiment of the present invention when the contacts are just in contact;

[0029] Figure 10 A cross-sectional view of the structure of an electromagnetic mechanism for a switching electrical appliance provided by an embodiment of the present invention when the contacts are in full contact;

[0030] In the accompanying drawings: 1, upper magnetic yoke assembly; 2, outer magnetic yoke assembly; 3, coil body assembly; 4, moving iron core assembly; 5, fastening washer; 6, return spring; 7, limit seat; 8, screw; 11, upper end cover; 12, inner magnetic yoke; 13, first bushing; 21, outer magnetic yoke; 22, lower end cover; 23, second bushing; 24, grounding fixing seat; 31, coil body; 32, coil skeleton; 33, lead end insert; 41, transmission rod; 42, pre-loaded block; 43, moving iron core ; 44. Overtravel spring; 45. Preload washer; 46. Adjusting washer; 47. Disc spring; 48. Flat washer; 49. Spring washer; 410. Self-locking nut; 121. Exhaust hole; 122. End face of inner yoke; 241. Threaded hole; 311. Lead wire; 321. Step; 331. Welding groove; 332. Threaded hole; 411. First step; 412. Second step; 413. Third step; 414. Flanged riveting; 431. End face of moving iron core. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] See also Figures 1 to 8 An embodiment of the present invention provides an electromagnetic mechanism for a switching electrical appliance, comprising a movable iron core assembly 4 that can be driven by a coil body assembly 3. The movable iron core assembly 4 comprises a transmission rod 41, an overtravel spring 44 sleeved on the transmission rod 41, and a movable iron core 43 sleeved on the overtravel spring 44. The transmission rod 41 has a first step 411 that abuts one end of the overtravel spring 44. When the coil body assembly 3 is energized, the movable iron core 43 drives the transmission rod 41 to move linearly. Preferably, the movable iron core assembly 4 further comprises a disc spring 47 and an adjustment washer 46 sleeved on the transmission rod 41. The transmission rod 41 has a second step 412 that abuts the disc spring 47. The adjustment washer 46 is located between the disc spring 47 and the second step 412. A preload washer 45 is provided between the adjustment washer 46 and the second step 412. A gap is provided between the second step 412 and the preload washer 45. In this embodiment, the overtravel spring 44 is designed in the moving iron core assembly 4 to facilitate indirect adjustment and ensure the pre-pressure value and final pressure value between the contacts when the switch is closed, and the characteristics of the disc spring 47 are matched with the force value of the overtravel spring 44 to reduce the impact force when the moving and static contacts of the switching electrical appliance come into contact with each other. The contact pre-pressure of the moving iron core assembly 4 can also be adjusted by adjusting the number of adjustment washers 46 during the assembly process. In addition, the moving iron core assembly 4 also includes components such as a pre-load block 42, a moving iron core 43, a pre-load washer 45, a flat washer 48, a spring washer 49, and a self-locking nut 410. During installation, the transmission rod 41 first passes through the upper magnetic yoke assembly 1, and then passes through the pre-load block 42, the overtravel spring 44, the moving iron core 43, the pre-load washer 45, the adjustment washer 46, the disc spring 47, the flat washer 48, the spring washer 49, and the self-locking nut 410 for assembly; the moving iron core assembly 4 includes an overtravel spring 44. In the initial state, the overtravel spring 44 is pre-compressed. The pre-pressure can be reflected as the initial pressure between the contacts of the switching electrical appliance. When the switch is closed and maintained, the compression amount of the overtravel spring 44 can be reflected as the final pressure between the contacts of the switching electrical appliance. Therefore, the initial pressure and final pressure between the contacts in the switching electrical appliance can be determined by separate tests of the pre-pressure and compression amount of the moving iron core assembly 4. Preferably, the moving iron core assembly 4 can be used as an independent component to undergo pressure testing, and the pressure test value can reflect the pre-pressure, final pressure, and over-travel value of the switch contact.

[0033] As an optimization solution of the embodiment of the present invention, please refer to Figure 7 and Figure 8 In addition to the first step 411 and the second step 412 mentioned in the above embodiment, the transmission rod 41 also has a third step 413. The first step 411 is in contact with the preload block 42 to limit the overtravel spring 44. The second step 412 leaves a gap with the preload washer 45. This gap ensures that the disc spring 47 exerts a reverse pull on the transmission rod 41 when the contacts of the switch are just in contact, thereby reducing the impact force during the closing collision. The third step 413 is in contact with the flat washer 48 to limit the disc spring 47. Preferably, the tail of the transmission rod 41 is fastened to the self-locking nut 410 by a flanged riveted 414 to prevent the self-locking nut 410 from loosening due to the impact of the disc spring 47 on the self-locking nut 410 during the frequent opening and closing movements of the electromagnetic mechanism. Preferably, the disc springs 47 are arranged in groups of three, with two groups facing each other, and a total of six groups with a total of eighteen pieces. The pre-pressure of the moving iron core assembly 4 is adjusted by adjusting the number of adjustment washers 46 during the assembly process. The pre-pressure can reflect the initial pressure when the contacts of the switching electrical appliance are just in contact.

[0034] As an optimization solution of the embodiment of the present invention, please refer to Figure 5 and Figure 6 The coil body assembly 3 includes a coil bobbin 32 and a coil body 31 wound on the coil bobbin 32. The transmission rod 41 passes through the coil bobbin 32. The movable iron core 43 slides in contact with the coil bobbin 32, and the movable iron core 43 at least partially extends into the coil bobbin 32. Preferably, the coil body assembly 3 further includes a lead terminal insert 33, which is embedded in the coil bobbin 32 and has a welding groove 331 and a threaded hole 332. In this embodiment, the coil body 31 is wound on the coil skeleton 32, and its lead wire 311 is inserted into the welding groove 331 of the lead end insert 33 through the hole on the coil skeleton 32; the lead end insert 33 is embedded in the coil skeleton 32, and has a welding groove 331 at one end and a threaded hole 332 at the other end to facilitate external wiring connection; a step 321 is designed inside the coil skeleton 32 to facilitate limiting the coil body assembly 3, and a fastening washer 5 is installed on the step 321 to fasten the coil body assembly 3 when the upper yoke assembly 1 and the outer yoke assembly 2 are bolted.

[0035] As an optimization solution of the embodiment of the present invention, please refer to Figures 1 to 4The electromagnetic mechanism further comprises an upper yoke assembly 1 and an outer yoke assembly 2, wherein the coil body assembly 3 is arranged inside the outer yoke assembly 2, and the upper yoke is mounted on the outer yoke assembly 2. Preferably, the upper yoke assembly 1 comprises an upper end cover 11 and an inner yoke 12, wherein the upper end cover 11 is mounted on the outer yoke assembly 2, the inner yoke 12 extends into the coil body assembly 3, and the inner yoke 12 has a first opening for the transmission rod 41 to extend into, and a first bushing 13 for lubrication and guidance is provided on the wall of the first opening, and the inner yoke 12 is installed with an interference fit with the first bushing 13. Preferably, an exhaust hole 121 is provided on the inner yoke 12. In this embodiment, the coil body assembly 3 is installed between the upper yoke assembly 1 and the outer yoke assembly 2, the upper end of the moving iron core assembly 4 is installed inside the upper yoke assembly 1, and the lower end is installed inside the coil body assembly 3 and the outer yoke assembly 2. The first bushing 13 can be an iron-based bushing, which has a lubricating and guiding function, reducing the wear of the transmission rod 41 and the upper magnetic yoke assembly 1 during movement; the upper end cover 11 and the inner magnetic yoke 12 are welded and fastened to reduce magnetic leakage; the inner magnetic yoke 12 is designed with an exhaust hole 121 to ensure smooth airflow during the movement of the moving iron core 43 and no resistance during movement; the upper end cover 11 and the inner magnetic yoke 12 are first rough-machined and then welded, and finally fine-machined into the upper magnetic yoke assembly 1, saving materials and ensuring assembly accuracy.

[0036] As an optimization solution of the embodiment of the present invention, please refer to Figures 1 to 4 The outer yoke assembly 2 includes an outer yoke 21 having an inner cavity and a lower end cap 22 disposed at the lower end of the outer yoke 21. The lower end cap 22 has a second opening for the transmission rod 41 to extend therethrough. A second bushing 23 for lubrication and guidance is disposed on the wall of the second opening. The lower end cap 22 and the second bushing 23 are installed with an interference fit. Preferably, a grounding mount 24 is welded to the outer yoke 21, and the grounding mount 24 has a threaded hole 241 disposed therein. In this embodiment, the design of the second bushing 23 avoids magnetic leakage, and an iron-based bushing can also be used, which has a lubricating and guiding function, ensuring that the moving iron core 43 is subjected to a stable electromagnetic attraction, reducing the wear of the moving iron core 43 and the outer yoke assembly 2 during movement; the outer yoke 21 and the lower end cover 22 are welded and fastened to reduce magnetic leakage; a grounding fixing seat 24 is welded on one side of the middle part of the outer yoke 21, and a threaded hole 241 is designed on the grounding fixing seat 24 to facilitate grounding of the metal shell of the electromagnetic mechanism; the outer yoke 21 and the lower end cover 22 are first rough-machined and then welded, and finally fine-machined into the outer yoke assembly 2, saving materials and ensuring assembly accuracy. Preferably, the transmission rod 41 is made of non-magnetic material, and the upper end cover 11, the inner yoke 12, the outer yoke 21, the lower end cover 22, and the moving iron core 43 are made of ferromagnetic material.

[0037] As an optimization solution of the embodiment of the present invention, please refer to Figure 1The electromagnetic mechanism also includes a limit seat 7 for fixing the upper magnetic yoke assembly 1 to the outer magnetic yoke assembly 2. The transmission rod 41 is also sleeved with a reset spring 6, and the reset spring 6 is located within the upper magnetic yoke assembly 1. In this embodiment, the reset spring 6 is installed between the moving iron core assembly 4 and the limit seat 7, and the reset spring 6 is limited by respective steps; the limit seat 7 is part of the switch electrical frame structure; without the reset spring 6 and the limit seat 7, the electromagnetic mechanism can be tested as an independent entity for electromagnetic holding force. The electromagnetic mechanism can be tested for electromagnetic holding force alone and for closing holding force when installed on the switch body. The data have a corresponding relationship, and it can be tested before the whole machine is assembled to avoid the disassembly workload caused by unqualified testing after installation, which reduces assembly efficiency.

[0038] As an optimization solution of the embodiment of the present invention, please refer to Figure 1 A fastening washer 5 is installed between the coil body assembly 3 and the upper yoke assembly 1, and the upper yoke assembly 1 and the outer yoke assembly 2 are fastened by screws 8. The fastening washer 5 is provided at the step 321, and fastens the coil body assembly 3 when the upper yoke assembly 1 and the outer yoke assembly 2 are bolted together.

[0039] The following is the working principle of this electromagnetic mechanism:

[0040] The electromagnetic mechanism is installed on the switch body, such as Figure 1 The figure shows the initial state of the electromagnetic mechanism. In this state, the overtravel spring 44 is pre-compressed, the disc spring 47 is compressed, the return spring 6 is pre-compressed, and the distance between the end face 431 of the movable iron core and the end face 122 of the inner magnetic yoke is S1+S2. When current is applied to the coil body 31, the movable iron core 4 overcomes the action of the return spring 6 and drives the transmission rod 41 to move upward. Figure 9 As shown, when the movable iron core 4 moves to the point where the contacts just make contact, the distance between the movable iron core end face 431 and the inner yoke end face 122 is S2, the movable iron core movement stroke is S1, and the contact movement stroke can be determined by S1. The reset spring 6 has been compressed and terminated. At this time, the transmission rod 41 remains in position, the overtravel spring 44 begins to compress, and the reaction force generated by the disc spring 47 begins to be released. At this time, the transmission rod 41 will be subjected to the thrust generated by the overtravel spring 44. Figure 10 As shown, when the moving iron core moves until its end face 431 is in contact with the end face 122 of the inner magnetic yoke, the closing process is completed, the overtravel spring 44 is compressed by S2, the overtravel of the contact closure can be determined by S2, and the final pressure of the contact closure can be determined by the compression amount S2, stiffness and pre-pressure of the overtravel spring.

[0041] When the contacts are fully closed, a resistor can be inserted into the control coil circuit to reduce the coil current and prevent overheating and burnout. When the coil body 31 is de-energized, the movable core end face 431 separates from the inner yoke end face 122. The overtravel spring 44 resets first, the disc spring 47 is compressed, and the return spring 6 drives the movable core assembly 4 back to its original position.

[0042] See also Figures 1 to 10 An embodiment of the present invention provides a switching device including the aforementioned electromagnetic mechanism. Using the aforementioned electromagnetic mechanism in a switching device can address the issues of poor pull-in voltage consistency, large closing bounce, severe wear and even jamming of moving parts, and large electromagnetic force divergence and attenuation, thereby improving the reliability of the switching device. The electromagnetic mechanism can be used as a single unit to measure the electromagnetic holding force, which corresponds to the closing holding force of the switch body. This allows for testing of the mechanism before assembly to ensure product quality.

[0043] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An electromagnetic mechanism for a switching device, comprising a moving iron core assembly driven by a coil assembly, characterized in that: The moving iron core assembly includes a transmission rod, an overtravel spring sleeved outside the transmission rod, and a moving iron core sleeved outside the overtravel spring. The transmission rod has a first step abutting against one end of the overtravel spring. After the coil body assembly is energized, it drives the moving iron core to drive the transmission rod to move linearly.

2. The electromagnetic mechanism for switching an electrical appliance according to claim 1, characterized in that: The moving iron core assembly also includes a disc spring and an adjustment washer mounted on the transmission rod, the transmission rod has a second step abutting against the disc spring, the adjustment washer is located between the disc spring and the second step, a preload washer is provided between the adjustment washer and the second step, and a gap is provided between the second step and the preload washer.

3. The electromagnetic mechanism for switching electrical equipment according to claim 1, wherein: The coil body assembly includes a coil frame and a coil body wound on the coil frame. The transmission rod passes through the coil frame, and the moving iron core at least partially extends into the coil frame.

4. The electromagnetic mechanism for switching an electrical appliance according to claim 3, wherein: The coil body assembly further comprises a lead end insert, which is embedded in the coil frame and is provided with a welding groove and a threaded hole.

5. The electromagnetic mechanism for switching electrical equipment according to claim 1, characterized in that: It also includes an upper magnetic yoke assembly and an outer magnetic yoke assembly. The coil body assembly is arranged in the outer magnetic yoke assembly, and the upper magnetic yoke is installed on the outer magnetic yoke assembly.

6. The electromagnetic mechanism for switching an electrical appliance according to claim 5, characterized in that: The upper magnetic yoke assembly includes an upper end cover and an inner magnetic yoke, the upper end cover is mounted on the outer magnetic yoke assembly, the inner magnetic yoke extends into the coil body assembly, and the inner magnetic yoke has a first opening for the transmission rod to extend into, and a first bushing for lubrication and guidance is provided on the hole wall of the first opening.

7. The electromagnetic mechanism for switching an electrical appliance according to claim 6, characterized in that: The inner magnetic yoke is provided with an exhaust hole.

8. The electromagnetic mechanism for switching an electrical appliance according to claim 5, wherein: The outer magnetic yoke assembly includes an outer magnetic yoke with an inner cavity and a lower end cover arranged at the lower end of the outer magnetic yoke. The lower end cover has a second opening for the transmission rod to extend into, and a second bushing for lubrication and guidance is provided on the hole wall of the second opening.

9. The electromagnetic mechanism for switching an electrical appliance according to claim 8, characterized in that: It also includes a limiting seat for fixing the upper magnetic yoke assembly on the outer magnetic yoke assembly. The transmission rod is also sleeved with a reset spring, and the reset spring is located in the upper magnetic yoke assembly.

10. A switch electrical device, characterized in that: Comprising the electromagnetic mechanism as described in any one of claims 1-9.

Images