Mining shock-resistant vacuum contactor and shock-resistant parameter optimization design method thereof

Abstract

The invention relates to a mining shock-resistant vacuum contactor and a shock-resistant parameter optimization design method thereof. The contactor comprises a vacuum arc-extinguishing chamber, moving and static contacts in the vacuum arc-extinguishing chamber, an electromagnetic driving mechanism and a contact spring. The contact spring applies contact pressure to the moving contact in a closing holding state, and the spring rigidity is configured to be lower than a standard pressure design value so as to reduce a secondary reaction force peak value when the armature collides with the iron core; the electromagnetic driving mechanism provides electromagnetic holding force for the moving contact in a closing holding state; the contactor further comprises a damping device which dissipates impact energy generated by external impact acceleration. The spring stiffness, the electromagnetic holding force and the damping characteristic are cooperatively configured, so that the bounce amplitude and duration of the contact under impact are jointly suppressed. According to the invention, the spring stiffness of the contact is properly reduced, and damping and electromagnetic retention are cooperatively configured, so that contact bounce under an impact working condition is effectively inhibited, and the reliability of the vacuum contactor in a coal mine working environment is improved.

Description

Technical Field

[0001] This invention relates to the field of mining electrical equipment technology; specifically, it relates to a mining shock-resistant vacuum contactor and its shock-resistant parameter optimization design method. Background Technology

[0002] Vacuum contactors are characterized by long lifespan, frequent operation, low noise, and small footprint. They are widely used in power plants and industrial and mining enterprises to control loads such as motors, transformers, or capacitors.

[0003] With the continuous improvement of automation level and coal mining machine power in recent years, the use of high-voltage and high-current contactors in coal mining machinery has been increasing. The starting of motor loads such as coal mining machines, scraper conveyors, transfer conveyors, and roadway belts are all related to contactors. Therefore, the operational stability of vacuum contactors is directly related to the safe and reliable operation of the above equipment. The high-vibration working environment unique to coal mining machines also puts forward higher requirements for the performance of contactors.

[0004] Under severe impact conditions, the moving and stationary contacts of a vacuum contactor may exhibit a bounce phenomenon, briefly separating and then re-closing, which directly threatens the reliability of the equipment. Therefore, how to suppress contact bounce under impact conditions and improve the operational stability and lifespan of the vacuum contactor has become an urgent engineering problem to be solved. Summary of the Invention

[0005] In view of this, the present invention provides a mining-use impact-resistant vacuum contactor and a method for optimizing its impact resistance parameters, thereby solving or at least alleviating one or more of the above-mentioned problems and other problems existing in the prior art.

[0006] To achieve the aforementioned objective, a first aspect of the present invention provides a mining-grade impact-resistant vacuum contactor, comprising a vacuum interrupter, a moving contact and a stationary contact disposed within the vacuum interrupter, an electromagnetic drive mechanism for driving the moving contact and the stationary contact, and a contact spring connected to the moving contact.

[0007] The contact spring is configured to apply contact pressure to the moving contact in the closed holding state, and the stiffness of the contact spring is configured to be lower than the standard pressure design value in order to reduce the peak value of the secondary reaction force P2 when the armature of the electromagnetic drive mechanism collides with the iron core.

[0008] The electromagnetic drive mechanism is configured to provide an electromagnetic holding force to the moving contact in the closed holding state;

[0009] The vacuum contactor also includes a damping device operatively associated with a contact system consisting of the moving contact, the stationary contact, the contact spring, and the armature, and configured to dissipate impact energy generated by external impact acceleration.

[0010] The stiffness of the contact spring, the electromagnetic holding force, and the damping characteristics of the damping device are configured in a coordinated manner so that the bounce amplitude and bounce duration of the moving contact relative to the stationary contact are jointly suppressed when subjected to external impact acceleration.

[0011] In the vacuum contactor described above, the reduced stiffness of the contact spring can optionally be achieved by reducing the spring wire diameter and increasing the effective number of turns.

[0012] In the vacuum contactor described above, optionally, the magnetic stiffness of the electromagnetic drive mechanism and the stiffness of the contact spring together constitute the equivalent stiffness of the contact system. When subjected to external impact acceleration, the magnetic stiffness helps to reduce the maximum bounce displacement of the moving contact.

[0013] The electromagnetic mechanism employs a permanent magnet holding structure or a dual-coil strong magnetic holding structure to enhance the electromagnetic holding force after the contacts are closed and to improve the magnetic stiffness.

[0014] In the vacuum contactor described above, the damping device may optionally include at least one of a damping pad, eddy current damping, buffer pad, or damping oil seal, for increasing the damping coefficient of the contact system to accelerate energy dissipation after contact collision.

[0015] To achieve the aforementioned objective, a second aspect of the present invention provides a method for optimizing the impact resistance parameters of a mining vacuum contactor contact system, wherein the method is used to manufacture a vacuum contactor as described in any one of the first aspects above, and the method includes the following steps:

[0016] Step S1: Establish a dynamic model of the vacuum contactor contact system. The model covers the coupling relationship between electromagnetic holding force, contact spring reaction force, equivalent damping, and external impact acceleration.

[0017] Step S2: Based on the aforementioned dynamic model, optimize the parameters of the contact system with the goal of reducing the bounce amplitude and bounce duration of the contact system under impact;

[0018] Step S3: Perform numerical solution and parameterized simulation on the dynamic model to obtain information on the displacement of the moving contact over time under different parameter configurations, and verify the effectiveness of parameter optimization;

[0019] Step S4: Manufacture the optimized vacuum contactor based on the simulation results;

[0020] The contact system parameter optimization strategy includes: under the premise that the contact static pressure meets the conductivity requirements, reducing the stiffness of the contact spring and the secondary reaction force P2, and coordinating the electromagnetic holding force characteristics and the equivalent damping, so that the bounce amplitude and bounce duration of the contact system when subjected to external impact acceleration are jointly suppressed.

[0021] In the method described above, optionally, the motion differential equation of the dynamic model is:

[0022]

[0023] in, It is a single mass block composed of an armature, a connecting rod, and a moving contact; This is the equivalent damping coefficient; For spring stiffness; This represents the amount of spring compression when the circuit is stable upon closing. For the real-time air gap between the moving and stationary contacts; To impact inertial force; For the armature in the air gap The electromagnetic attraction generated at that time.

[0024] In the method described above, optionally, based on the dynamic model, the maximum bounce displacement of the contact system is analyzed and obtained as follows:

[0025]

[0026] in, To achieve peak impact acceleration, For the pulse width, For the equivalent stiffness of the contact system, For magnetic stiffness, The damping ratio of the contact system;

[0027] The bounce amplitude under different parameter configurations is calculated using the formula for the maximum bounce displacement, which is then used for parameter optimization.

[0028] In the method described above, optionally, the impact acceleration is set to a half-sine pulse form in the simulation to simulate the impact conditions of the coal mining face.

[0029] In the aforementioned method, optionally, the optimization strategy reduces the contact spring stiffness and secondary reaction force P2 by reducing the wire diameter of the contact spring and increasing the effective number of turns, until the simulated contact secondary bounce duration is less than a preset threshold.

[0030] In the aforementioned method, optionally, when configuring the electromagnetic holding force characteristics, the number of turns of the electromagnetic mechanism winding is simultaneously optimized to increase the magnetic stiffness and electromagnetic holding force synchronously, so as to compensate for the decrease in equivalent stiffness caused by the reduction in contact spring stiffness, thereby maintaining the impact resistance of the contact system.

[0031] The mine-use impact-resistant vacuum contactor of the present invention effectively suppresses contact bounce under impact conditions by appropriately reducing the stiffness of the contact spring and coordinating the configuration of damping and electromagnetic holding force, thereby improving the reliability of the vacuum contactor in the high-vibration working environment of coal mines.

[0032] The present invention further provides a method for optimizing the impact resistance parameters of a mining vacuum contactor contact system for manufacturing the above-mentioned vacuum contactor, and therefore this method also has the above-mentioned advantages. Attached Figure Description

[0033] The disclosure of this invention will become more apparent from the accompanying drawings. It should be understood that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings:

[0034] Figure 1 This is a schematic diagram of the structure of one embodiment of the mine-use impact-resistant vacuum contactor of the present invention;

[0035] Figure 2 This is a schematic diagram of the vacuum interrupter chamber in one embodiment of the mine-use impact-resistant vacuum contactor of the present invention;

[0036] Figure 3 This is a schematic diagram of the air gap simulation curve in one embodiment of the impact resistance parameter optimization design method for the contact system of the mining vacuum contactor of the present invention.

[0037] Figure 4 This is a schematic diagram of the spring parameters before optimization in one embodiment of the impact resistance parameter optimization design method for the contact system of a mining vacuum contactor of the present invention.

[0038] Figure 5 This is a schematic diagram of optimized spring parameters in one embodiment of the impact resistance parameter optimization design method for the contact system of a mining vacuum contactor according to the present invention.

[0039] Reference numerals: 11-Lower outgoing terminal; 12-Upper outgoing terminal; 13-Secondary wiring terminal; 21-Vacuum interrupter; 31-Direct drive electromagnetic mechanism; 41-Control circuit board; 211-Metallized ceramic shell; 212-Bellowette; 213-Moving contact; 214-Stationary contact. Detailed Implementation

[0040] Referring to the accompanying drawings and specific embodiments, the structure, composition, features, and advantages of the mine-use impact-resistant vacuum contactor and its impact-resistant parameter optimization design method of the present invention will be described below by way of example. However, all descriptions should not be construed as limiting the present invention in any way.

[0041] Furthermore, for any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature shown or implied in the various figures, the present invention still allows for any combination or deletion of these technical features (or their equivalents) without any technical obstacle, and thus these further embodiments according to the present invention should also be considered within the scope of this description.

[0042] It should also be noted that the orientations or positional relationships indicated herein are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the purpose of facilitating the description of this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure.

[0043] It should also be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0044] Figure 1 and Figure 2 This is a schematic diagram of one embodiment of the mine-use impact-resistant vacuum contactor of the present invention.

[0045] Figure 1 A typical cross-sectional view of the 3.6kV vacuum contactor of this embodiment is shown, which includes an electromagnetic drive mechanism (in this embodiment, a direct-drive electromagnetic mechanism 31, including components such as an armature, iron core, and coil), a vacuum interrupter 21, a control circuit board 41, and components such as a lower outgoing terminal 11, an upper outgoing terminal 12, and a secondary wiring terminal 13. The electromagnetic drive mechanism is used to drive the moving contact and the stationary contact to complete the closing and opening operation, and its armature is connected to the moving contact through a connecting rod.

[0046] Figure 2The structural details of the vacuum interrupter 21 are further shown, including the moving contact 213 and stationary contact 214 disposed within the vacuum interrupter 21, as well as components such as the bellows 212 and the metallized ceramic shell 211. The contact spring is connected to the moving contact 213. In the closed-end state of the vacuum contactor, the moving contact 213 is pulled by the electromagnetic attraction generated by the electromagnetic drive mechanism to make close contact with the stationary contact 214, and a certain contact pressure is provided by the contact spring. The closing spring is compressed and stores energy after the contacts are closed, providing continuous contact pressure to the contacts, while the opening spring is used to quickly open the contacts when power is cut off.

[0047] In this embodiment, the stiffness of the contact spring is configured to be lower than the standard pressure design value, specifically achieved by reducing the spring wire diameter and increasing the effective number of coils. For example, the standard design value is a spring wire diameter of 3mm, an effective number of coils of 6, and a spring stiffness of 4.94N / mm. The spring wire diameter can be appropriately reduced to 2.8mm, and the effective number of coils can be appropriately increased to 6.5, thereby reducing the spring stiffness to 3.46N / mm, and thus reducing the secondary reaction force P2 from 185.1N to 173N. This configuration is used to reduce the peak value of the secondary reaction force P2 when the armature of the electromagnetic drive mechanism collides with the iron core. Here, the secondary reaction force P2 refers to the reaction force generated during the secondary spring-opening process of the contact after the armature impacts the iron core.

[0048] The vacuum contactor also includes a damping device operatively connected to the contact system consisting of a moving contact 213, a stationary contact 214, a contact spring, and an armature. This damping device dissipates the impact energy generated by external impact acceleration. In optional embodiments, the damping device may exemplarily employ auxiliary energy dissipation measures such as damping pads, eddy current damping, buffer pads, or damping oil seals to increase the damping coefficient and damping ratio of the contact system. The function of the damping device is that, when impact acceleration occurs, the damping force can dissipate the collision energy and suppress the vibration amplitude of the contact system.

[0049] The electromagnetic drive mechanism generates an electromagnetic attraction force, which acts on the moving contact 213 to provide an electromagnetic holding force in the closed holding state. The stiffness of the contact spring, the electromagnetic holding force, and the damping characteristics of the damping device are configured in a coordinated manner so that the bounce amplitude and bounce duration of the moving contact 213 relative to the stationary contact 214 are jointly suppressed when subjected to external impact acceleration.

[0050] In optional embodiments, the electromagnetic drive mechanism employs a permanent magnet holding structure or a dual-coil strong magnetic holding structure to enhance the electromagnetic holding force after the contacts close and improve the magnetic stiffness. The magnetic stiffness, together with the stiffness of the contact spring, constitutes the equivalent stiffness of the contact system, which helps to reduce the maximum bounce displacement of the moving contact 213. The magnetic stiffness reflects the sensitivity of the electromagnetic attraction force to changes in the air gap, characterizing the ability of the electromagnetic holding force to resist changes in the air gap after the contacts close.

[0051] This embodiment is designed based on the contact bounce principle under impact conditions of a vacuum contactor. When the vacuum contactor is in the closed holding state, and the entire contactor is subjected to a sudden impact force along the contact movement direction, the moving contact assembly experiences a delayed response due to inertia, generating an inertial force. When this inertial force exceeds the resultant force of the electromagnetic attraction and the spring reaction force, the originally closed contacts momentarily separate, resulting in a bounce phenomenon. During normal closing, the electromagnetic attraction generated by the coil energization overcomes the spring preload, causing the armature to drive the contacts to close and conduct the main circuit. After the armature contacts the iron core, it enters a stable holding state. If a vertically upward impact is received at this time, the acceleration will cause the armature and contact moving parts to collide or separate relative to the stationary iron core.

[0052] The bouncing process is essentially an underdamped vibration response of the contact-spring-armature vibration system to a transient impact. Under impact, the moving contact 213 first accelerates away from the stationary contact 214 to reach its maximum displacement, and then is pulled back under the combined action of electromagnetic attraction and spring force, accompanied by damped vibration until stable contact is restored. If the impact force is large, the contact will undergo one or more separations and closed cycles (bouncing); if the impact inertial force is insufficient to overcome the contact holding force, separation will not occur, only slight vibration will be generated. It can be seen that the bouncing of the contact is the result of the ratio of the contact electromagnetic force, the contact holding force, and the impact inertial force, as well as the energy dissipation and damping of the collision.

[0053] Impact-triggered bounce typically involves two bounce processes. The first bounce refers to the process where the contact spring's restoring force causes the contact to quickly spring open after the moving and stationary contacts close, which is consistent with conventional closing bounce. The second bounce refers to the secondary opening of the contact caused by the rebound of the armature after impacting the iron core. Therefore, this embodiment reduces the recoil force when the armature closes (i.e., reduces the peak force P2) by appropriately adjusting the contact spring structure, which can alleviate the secondary contact collision and reduce the bounce duration. At the same time, the output capability of the electromagnetic system is increased. Options include enhancing the attractive force of the armature at a smaller air gap or using a permanent magnet holding structure with greater holding force, so that there is a greater pulling force when the contacts want to separate, prompting them to re-close more quickly, thus reducing the bounce amplitude and bounce time.

[0054] In this embodiment, the inherent characteristics of the system change after the contact spring stiffness is reduced. The equivalent stiffness of the system is the superposition of the mechanical spring stiffness and the magnetic stiffness, and the natural frequency of the system is determined by the equivalent stiffness and the overall mass of the moving contact assembly. Reducing the spring stiffness itself makes the contact system more compliant, thereby buffering kinetic energy under impact and reducing the severity of the first bounce; at the same time, the reduction of spring stiffness directly reduces the peak value of the secondary reaction force P2 when the armature collides with the iron core, thereby effectively suppressing the amplitude of the second bounce. Meanwhile, by increasing the damping coefficient through the damping device, the damping ratio of the system is increased, which can accelerate the vibration decay rate and avoid contact hysteresis or long-term oscillation caused by spring softening. The enhancement of the electromagnetic holding force compensates for the decrease in equivalent stiffness caused by the reduction of spring stiffness by increasing the magnetic stiffness, thereby maintaining the impact resistance of the contact system and enabling the vacuum contactor of this embodiment to operate stably in the high-vibration working environment of coal mines.

[0055] Another embodiment of the present invention discloses a method for optimizing the impact resistance parameters of a contact system for a mining vacuum contactor, which can be used to manufacture the aforementioned vacuum contactor, and includes the following specific steps.

[0056] Step S1: Establish a dynamic model of the contact system. This model encompasses the coupling relationship between electromagnetic holding force, contact spring reaction force, equivalent damping, and external impact acceleration. The following describes the specific process of establishing the model and performing analysis based on it in this embodiment.

[0057] Since the armature, connecting rod, and moving contact 213 are rigidly connected, they will all undergo overall translation upon impact. Therefore, these components can be considered as a single mass block m. In the "closed-holding" state, the static equilibrium condition of the vacuum contactor is: electromagnetic attraction... Equal to spring force (Ignoring the effects of gravity).

[0058] Based on the above conditions, the differential equation of motion of the contact system under the action of impact acceleration a(t) is established according to d'Alembert's principle:

[0059]

[0060] Where m is the integral mass block composed of armature, connecting rod and moving contact 213; c is the equivalent damping coefficient, including contact collision energy loss and internal friction damping of the system; k is the equivalent stiffness of the spring. The compression of the spring when the circuit is stable is a constant; g(t) is the real-time air gap between the moving and stationary contacts, and g(t) = 0 when the contacts are in contact; ma(t) is the impact inertial force, which is opposite to the acceleration. This is the electromagnetic attraction force generated by the armature when the air gap is g, which changes with the air gap g.

[0061] In equation (1), Represents the inertial force of mass. This refers to damping energy dissipation, including friction, eddy currents, and other energy dissipation, which plays a role in suppressing changes. This represents the restoring force of the spring. Indicates electromagnetic attraction. The force represents the impact inertial force. In equation (1), the left side represents the sum of the inertial force, damping force and spring force of the contact moving parts, and the right side represents the difference between the driving force and the equivalent external excitation force.

[0062] Step S2, based on the dynamic model, analyzes the contact bounce behavior of the vacuum contactor under impact conditions, thereby optimizing the contact system parameters to reduce the bounce amplitude and duration under impact. As an example, the specific analysis process in this embodiment is as follows.

[0063] The equilibrium state and the impact state are analyzed separately below:

[0064] When there is no impact, the system is in equilibrium, g(t)=0, a(t)=0. Substituting these values ​​into equation (1) yields the steady-state equilibrium condition:

[0065]

[0066] in, The electromagnetic holding force is equal to the spring force generated by the pre-compression. At this time, the contact is in the normal closed holding state.

[0067] Generally, electromagnetic attraction decreases sharply as the air gap increases. To analyze the system response under small disturbances, let... This represents the instantaneous air gap. Electromagnetic force in... Perform a first-order Taylor expansion at this point:

[0068]

[0069] Substituting equation (3) and equilibrium relationship (2) into equation (1), and retaining the inertia and damping terms, we obtain the minimum disturbance linear equation:

[0070]

[0071] It can be seen from equation (4) that the equivalent stiffness The mechanical spring stiffness k and magnetic stiffness This collective determination indicates that the magnetic circuit itself possesses spring-like characteristics, with the attractive force changing more rapidly the closer it gets to the closed position. The damping 'c' in the formula comprehensively includes energy dissipation from friction, eddy currents, and collisions, as well as external excitation. It can be regarded as a half-sine pulse, inducing underdamped vibration.

[0072] Based on equation (4), the system's natural frequency can be calculated. Damping ratio Let the peak impact acceleration be... The pulse width is Using the energy analysis method for a linear second-order system under velocity excitation, the maximum bounce displacement can be obtained as:

[0073]

[0074] when When this occurs, it indicates that the contacts have separated, resulting in a bounce. The critical air gap is typically around 5 mm. From equation (5), it can be seen that if the value of k is increased to pursue higher contact pressure, then... Increase, reduce, Increased size makes bouncing more likely; if the electromagnetic holding force is increased... Increase magnetic stiffness Then it can be reduced If the value of k is reasonably reduced while the magnetic stiffness is increased through design; Or damping c to maintain and Matching also helps reduce peak displacement and accelerate decay. Therefore, this embodiment yields an optimized strategy of reducing spring stiffness k to lower the peak value of P2 while simultaneously strengthening electromagnetic holding and damping. When reducing spring stiffness, it is necessary to ensure that the contact static pressure meets conductivity requirements.

[0075] It should be noted that, for the sake of simplifying the analysis, the model in this embodiment assumes that: the electromagnetic force and spring force are balanced and there is no relative velocity when the contacts initially close; the collision stiffness between the contacts is much greater than the spring stiffness; and the influence of high-frequency vibration and short arc at the moment of collision on the overall motion is negligible. Therefore, the model in this embodiment only considers the response of the low-frequency dominant vibration mode of contact-spring-mass. This model reflects the contact bounce trend and main characteristics caused by impact, providing a reference for subsequent analysis and optimization.

[0076] Step S3 involves numerically solving and parametrically simulating the dynamic model to obtain information on the displacement of the moving contact over time under different parameter configurations, thus verifying the effectiveness of parameter optimization. For example, the simulation solution process is described below.

[0077] The aforementioned dynamic model was numerically solved using Matlab. Due to the very short bounce time, a small fixed step size (e.g., ...) was adopted. To ensure calculation accuracy, the impact acceleration a(t) is generated according to a typical half-sine impact load, and its expression is:

[0078]

[0079] In this embodiment, to simulate the severe impact conditions encountered in a coal mine working environment, the peak acceleration value is set to... (Here, g represents gravitational acceleration, but unless otherwise specified, g in other parts of this article still refers to the air gap between the moving and stationary contacts.) Duration value .

[0080] At least two simulation conditions are set for comparison. This embodiment sets up two conditions: the original design condition and the optimized design condition (compared to the original design, the spring stiffness is reduced and the preload is adjusted accordingly). For example, the parameter settings are shown in Table 1 below.

[0081] Table 1 Simulation Parameter Settings

[0082]

[0083] As shown in Table 1, the parameter differences between the optimized and original operating conditions in this example are as follows: Depend on Reduced to N / m, Increase the value while keeping the other parameters unchanged.

[0084] The above parameters give the original system high stiffness and low damping. The optimized scheme reduces the spring stiffness while appropriately increasing the damping to reduce contact bounce. The equivalent stiffness of the spring under the original design conditions is taken as... The original contact P2 had a relatively large force; after optimization, the spring stiffness decreased by approximately 25%. The spring is softened appropriately to reduce the peak value of P2. Meanwhile, to address the issue that softening the spring might lead to a decrease in the system's damping ratio, auxiliary energy-dissipating measures are introduced, such as using damping pads or eddy current damping, to increase the damping coefficient, thereby improving the damping ratio.

[0085] Figure 3 The simulation curves (air gap-time curves) of the moving contact displacement versus time under the original design conditions and optimized design conditions under the aforementioned half-sine impact parameters are shown. The solid line represents the contact response under the original spring parameters, and the dashed line represents the response under the optimized spring parameters. It can be seen that under an impact excitation of 50g (where g is the acceleration due to gravity, not the air gap between the moving and stationary contacts) and 6ms, both conditions exhibit a significant contact separation and bounce, but their dynamic characteristics differ significantly.

[0086] Depend on Figure 3 The simulation curves shown allow for quantitative analysis of the bounce process. For the original design, the contact begins to be pulled apart by inertia around t≈6ms, until... The maximum separation displacement is reached at approximately 16.7 ms. ≈3.36mm, then oscillated and returned under the action of spring and electromagnetic force, and at It basically returned to a stable closure after approximately 35.9ms. Its bounce duration is approximately... The time is approximately 29.9 ms, during which the contact may collide rapidly multiple times. In contrast, the peak value of the curve is significantly reduced under the optimized design conditions, and the maximum bounce displacement is... ≈2.44mm; simultaneously, the contact begins to decelerate and return to its original position relatively early. It regained stable contact in approximately 24.1ms, reducing the bounce duration by about 19%. The optimized contact bounce amplitude and time were significantly reduced, resulting in a substantial improvement in impact resistance.

[0087] The above comparison clearly demonstrates the influence of spring parameters on contact bounce behavior: springs with higher stiffness and greater preload result in smaller contact bounce amplitude but higher response frequency and more violent impact, making secondary rebound more likely; with a suitable reduction in stiffness, the contact system becomes more compliant, able to buffer kinetic energy under impact and reduce the severity of the initial bounce, but sufficient damping and electromagnetic force are required to prevent prolonged oscillation. This embodiment takes this trade-off into account, slightly reducing the peak impact reaction force by slightly reducing spring stiffness, while increasing damping and ensuring electromagnetic holding force to prevent spring softening that could lead to contact lag or prolonged oscillation, thus achieving a simultaneous decrease in bounce amplitude and duration.

[0088] Step S4: Manufacture the optimized vacuum contactor based on the simulation results. Machin the contact spring according to the optimized parameters determined by the simulation analysis.

[0089] Figure 4 and Figure 5 The spring parameters before and after optimization under the aforementioned exemplary parameter schemes are shown respectively. For example... Figure 4 and Figure 5 As shown, the spring wire diameter can be reduced from 3mm to 2.8mm, and the effective number of turns can be increased from 6 turns to 6.5 turns, resulting in a decrease in stiffness from 4.94N / mm to 3.46N / mm and a decrease in secondary reaction force P2 from 185.1N to 173N. By reducing the P2 force of the opening spring, the resistance during closing and holding is reduced. Simultaneously, optimizing the number of turns in the electromagnetic mechanism winding increases the magnetic stiffness and electromagnetic holding force synchronously, compensating for the decrease in equivalent stiffness caused by the reduced contact spring stiffness, thereby maintaining the contact system's impact resistance.

[0090] This embodiment also includes actual measurement and verification of the vacuum contactor, conducting impact tests on the vacuum contactor before optimization and the vacuum contactor after re-engineering the spring parameters. For example, the measured impact response data before and after the optimization of the above parameter scheme are as follows: Before optimization, under an impact of 50g (where g is the gravitational acceleration), the contactor experienced a 7ms interruption; after optimization, the interruption lasted only 2ms, significantly reducing the interruption time.

[0091] The impact-resistant parameter optimization design method in this embodiment establishes a dynamic model of the contact system coupled with electromagnetic force, spring, and impact acceleration. Numerical simulation and parameter optimization are then performed, and the results are verified on actual products. This effectively suppresses contact bounce under impact conditions, improving the operational stability and lifespan of the vacuum contactor. By appropriately reducing the contact spring stiffness and preload (reducing the peak value of P2 reaction force), supplemented by increasing damping and enhancing electromagnetic holding force, impact bounce is significantly suppressed. This optimization achieves rapid contact stabilization after impact by mitigating contact collision recoil and accelerating energy dissipation, making it suitable for coal mine working environments with strong impact conditions.

[0092] To improve the impact resistance of vacuum contactors, some embodiments of the present invention employ the following measures: reducing the contact spring stiffness or final pressure to reduce secondary impacts (the contact static pressure meets conductivity requirements); using permanent magnet holding or double-coil strong magnetic holding to increase the torque after contact closure; and increasing mechanical damping (such as buffer pads, damping oil seals, etc.) to absorb impact energy. Furthermore, some embodiments of the present invention combine the above measures to effectively reduce the contact bounce amplitude and the number of bounces.

[0093] The technical scope of this invention is not limited to the contents of the above specification. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the scope of this invention.

Claims

1. A mining-grade impact-resistant vacuum contactor, characterized in that, It includes a vacuum interrupter, a moving contact and a stationary contact disposed within the vacuum interrupter, an electromagnetic drive mechanism for driving the moving contact and the stationary contact, and a contact spring connected to the moving contact; The contact spring is configured to apply contact pressure to the moving contact in the closed holding state, and the stiffness of the contact spring is configured to be lower than the standard pressure design value in order to reduce the peak value of the secondary reaction force P2 when the armature of the electromagnetic drive mechanism collides with the iron core. The electromagnetic drive mechanism is configured to provide an electromagnetic holding force to the moving contact in the closed holding state; The vacuum contactor also includes a damping device operatively associated with a contact system consisting of the moving contact, the stationary contact, the contact spring, and the armature, and configured to dissipate impact energy generated by external impact acceleration. The stiffness of the contact spring, the electromagnetic holding force, and the damping characteristics of the damping device are configured in a coordinated manner so that the bounce amplitude and bounce duration of the moving contact relative to the stationary contact are jointly suppressed when subjected to external impact acceleration.

2. The vacuum contactor as described in claim 1, characterized in that, The reduction in contact spring stiffness is achieved by decreasing the spring wire diameter and increasing the effective number of coils.

3. The vacuum contactor as described in claim 1, characterized in that, The magnetic stiffness of the electromagnetic drive mechanism and the stiffness of the contact spring together constitute the equivalent stiffness of the contact system. When subjected to external impact acceleration, the magnetic stiffness helps to reduce the maximum bounce displacement of the moving contact. The electromagnetic mechanism employs a permanent magnet holding structure or a dual-coil strong magnetic holding structure to enhance the electromagnetic holding force after the contacts are closed and to improve the magnetic stiffness.

4. The vacuum contactor as described in claim 1, characterized in that, The damping device includes at least one of a damping pad, eddy current damping, buffer pad, or damping oil seal, used to increase the damping coefficient of the contact system to accelerate energy dissipation after contact collision.

5. A method for optimizing the impact resistance parameters of a mining vacuum contactor contact system, characterized in that, The method is used to manufacture a vacuum contactor as described in any one of claims 1-4, and the method includes the following steps: Step S1: Establish a dynamic model of the vacuum contactor contact system. The model covers the coupling relationship between electromagnetic holding force, contact spring reaction force, equivalent damping, and external impact acceleration. Step S2: Based on the aforementioned dynamic model, optimize the parameters of the contact system with the goal of reducing the bounce amplitude and bounce duration of the contact system under impact; Step S3: Perform numerical solution and parameterized simulation on the dynamic model to obtain information on the displacement of the moving contact over time under different parameter configurations, and verify the effectiveness of parameter optimization; Step S4: Manufacture the optimized vacuum contactor based on the simulation results; The contact system parameter optimization strategy includes: under the premise that the contact static pressure meets the conductivity requirements, reducing the stiffness of the contact spring and the secondary reaction force P2, and coordinating the electromagnetic holding force characteristics and the equivalent damping, so that the bounce amplitude and bounce duration of the contact system when subjected to external impact acceleration are jointly suppressed.

6. The method as described in claim 5, characterized in that, The equations of motion for the dynamic model are as follows: in, It is a single mass block composed of an armature, a connecting rod, and a moving contact; This is the equivalent damping coefficient; For spring stiffness; This represents the amount of spring compression when the circuit is stable upon closing. For the real-time air gap between the moving and stationary contacts; To impact inertial force; For the armature in the air gap The electromagnetic attraction generated at that time.

7. The method as described in claim 5, characterized in that, Based on the aforementioned dynamic model, the maximum bounce displacement of the contact system is obtained as follows: in, To achieve peak impact acceleration, For the pulse width, For the equivalent stiffness of the contact system, For magnetic stiffness, The damping ratio of the contact system; The bounce amplitude under different parameter configurations is calculated using the formula for the maximum bounce displacement, which is then used for parameter optimization.

8. The method as described in claim 5, characterized in that, In the simulation, the impact acceleration is set to a half-sine pulse form to simulate the impact conditions at the coal mining face.

9. The method as described in claim 5, characterized in that, In the optimization strategy, the stiffness of the contact spring and the secondary reaction force P2 are reduced by decreasing the wire diameter of the contact spring and increasing the effective number of turns, until the simulated duration of the secondary bounce of the contact is less than a preset threshold.

10. The method as described in claim 5, characterized in that, In the optimization strategy, when configuring the electromagnetic holding force characteristics, the number of turns of the electromagnetic mechanism winding is optimized simultaneously so that the magnetic stiffness and electromagnetic holding force increase synchronously to compensate for the decrease in equivalent stiffness caused by the reduction in contact spring stiffness, thereby maintaining the impact resistance of the contact system.

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