Electromagnetic system for contactor

Abstract

The electromagnetic system comprises a contact support, an armature, a counter-force spring, a partition plate, a magnet yoke, a coil framework, an iron core and a circuit board, the armature is connected with the contact support through a clamping plate, the counter-force spring is arranged on the upper surface of the partition plate, the partition plate is arranged between the contact support and the magnet yoke, and the coil framework is arranged on the upper surface of the partition plate. The magnetic yoke comprises an upper magnetic yoke and a lower magnetic yoke, the coil framework and the iron core are arranged between the upper magnetic yoke and the lower magnetic yoke, the upper surface of the upper magnetic yoke is attached to the lower bottom surface of the partition plate, and the circuit board is provided with an MCU processing unit and an MOS tube power output unit. Compared with the prior art, the utility model solves the problems of high energy consumption, high temperature rise, high requirement on the stability of a power grid and the like of a traditional alternating current contactor electromagnetic system in a use environment, improves the efficiency and the service life of the contactor, and also improves the stability of a whole power system and the economic benefits of enterprises.

Description

Technical Field

[0001] The utility model relates to the field of contactors, in particular to an electromagnetic system for contactors. Background Art

[0002] Contactors are divided into AC contactors (voltage AC) and DC contactors (voltage DC), and are used in power, distribution, and consumption. The operation of an AC contactor depends on the electromagnetic field generated by its coil, which controls the on and off of the main contacts through electromagnetic attraction and release. For an AC-controlled contactor, when the AC current passes through zero, the electromagnetic attraction of the iron core on the armature in the magnetic circuit of the AC coil becomes zero. At this time, the armature retreats a short distance under the action of the reaction spring. When the current passes through zero and begins to attract again, the pole face of the iron core vibrates, and the AC-controlled contactor emits noise. Therefore, to eliminate this vibration, AC-controlled contactors install magnetic rings on the pole face of the iron core. This ensures that the magnetic flux is not zero when the AC current passes through zero, ensuring the attraction of the armature and the iron core. However, this measure still cannot completely eliminate noise, and traditional AC-controlled contactors still have slight vibration noise. For DC control contactors, DC coils generate significant heat, so they have many turns and thinner enameled wire, resulting in higher DC resistance. This ensures the core can generate sufficient suction force on the armature when operating at the rated DC voltage, and the coils are typically wound into a slender shape. Furthermore, for coils of the same power, DC coils are larger than AC coils. The overall height of a contactor using a DC coil can be up to twice that of an AC coil, limiting its size in installation environments with limited space. Traditional DC coils using a solenoid core, when DC voltage is applied across the coil, generate a current determined by the coil's resistance. Since copper has a very low resistivity, to ensure the current is moderate when the armature is held and to reduce the holding power, the coils are often designed with thin wire and many turns. This results in higher resistance, bulk, and weight, leading to higher cost.

[0003] The contactor's DC control solenoid coil is equipped with a magnetic yoke to enhance the coil's pull and confine the magnetic force generated by the coil. To improve electromagnet efficiency, traditional DC control contactors typically design their yokes to fully enclose the DC coil on all four sides. However, during the pull-in and hold-in processes of traditional contactor DC coils, the continuous high current causes the coil to heat up within the enclosed environment, impacting the contactor's lifespan and performance. Operating in high-temperature environments accelerates the aging of insulation materials and increases failure rates.

[0004] Traditional contactor coils require high currents in both the closing and holding states. The current is particularly high when closing, and while the current slightly decreases during the holding state, it remains high, resulting in consistently high energy consumption. In some automated equipment and production lines, frequent contactor operation (frequent closing and releasing) further increases the system's overall energy consumption. High-energy-consuming equipment increases overall electricity consumption, indirectly leading to increased greenhouse gas emissions, which is detrimental to the environment. Furthermore, high energy consumption directly translates into higher electricity bills, making energy costs a significant operating expense for businesses. Utility Model Content

[0005] The purpose of the present invention is to provide an electromagnetic system for a contactor in order to overcome the defects of the prior art, thereby improving the performance and life of the contactor.

[0006] The purpose of the utility model can be achieved through the following technical solutions:

[0007] An electromagnetic system for a contactor includes a contact support, an armature, a reaction spring, a partition, a yoke, a coil skeleton, an iron core, and a circuit board. The armature is connected to the contact support via a clamping plate. The reaction spring is arranged on the upper surface of the partition. The partition is arranged between the contact support and the yoke. The yoke includes an upper yoke and a lower yoke. The coil skeleton and the iron core are arranged between the upper yoke and the lower yoke. The upper surface of the upper yoke is fitted with the lower bottom surface of the partition. The circuit board is provided with an MCU processing unit and a MOS tube power output unit.

[0008] Furthermore, a moving contact is provided on the contact support.

[0009] Furthermore, a contact spring is provided between the moving contact and the contact support.

[0010] Furthermore, a limiting feature for the reaction spring is provided on the upper surface of the partition.

[0011] Furthermore, the four corners of the partition are arranged on the base of the contactor.

[0012] Furthermore, the upper magnetic yoke is of U-shaped design and is installed with interference fit with the lower magnetic yoke through installation notches on both sides.

[0013] Furthermore, the lower magnetic yoke is provided with a coil skeleton installation positioning hole for fixing the coil skeleton.

[0014] Furthermore, the coil frame is positioned through the coil frame installation positioning hole and is fitted on the upper surface of the lower magnetic yoke.

[0015] Furthermore, an iron core is inserted into the coil frame, and the iron core is riveted to the upper surface of the lower magnetic yoke.

[0016] Furthermore, the lower bottom surface of the lower magnetic yoke is arranged in the base of the contactor.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The utility model adopts a semi-enclosed magnetic yoke, which reduces the coil temperature rise caused by continuous current during the contactor's attraction and holding process, and effectively slows down the aging rate of the electromagnetic system insulation material working in a high temperature environment, thereby improving the performance and life of the contactor.

[0019] 2. The circuit board of the utility model is equipped with an MCU processing unit and a MOS tube power output unit. The main power supply voltage is collected through A / D analog-to-digital conversion. The duty cycle of the PWM signal of the pull-in and hold is adjusted according to the size of the power supply voltage and the preset control algorithm. In this way, the power of the contactor during and after the pull-in is controlled, thereby improving the energy efficiency level of the contactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of an electromagnetic system for a contactor proposed in the utility model;

[0021] Figure 2 This is a schematic diagram of the working state of the electromagnetic system for a contactor proposed in the utility model, wherein (2a) is the initial state and (2b) is the holding state;

[0022] Figure 3 This is a structural schematic diagram of a semi-enclosed magnetic yoke of an electromagnetic system for a contactor proposed by the utility model.

[0023] Legend: 1. Contact support; 2. Contact spring; 3. Moving contact; 4. Armature; 5. Reaction spring; 6. Partition; 7. Upper yoke; 8. Coil frame; 9. Iron core; 10. Lower yoke; 11. Circuit board. DETAILED DESCRIPTION

[0024] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0025] This embodiment provides an electromagnetic system for a contactor, and its structural diagram is shown in FIG. Figure 1As shown, it includes a contact support 1, an armature 4, a reaction spring 5, a partition 6, a yoke, a coil bobbin 8, an iron core 9, and a circuit board 11. The armature 4 is connected to the contact support 1 through a clamping plate. The reaction spring 5 is arranged on the upper surface of the partition 6. The partition 6 is arranged between the contact support 1 and the yoke. The yoke includes an upper yoke 7 and a lower yoke 10. The lower bottom surface of the lower yoke 10 is arranged in the base of the contactor. The lower yoke 10 is provided with a coil bobbin mounting positioning hole and is riveted to the iron core 9. The coil bobbin 8 is inserted into the iron core 9 and is positioned and installed in a fit with the lower yoke 10 through the positioning holes. The upper yoke 7 is U-shaped and is installed with an interference fit with the lower yoke 10 through the mounting notches on both sides to ensure the connectivity of the magnetic circuit after the upper and lower yokes are installed. A partition 6 is installed between the contact support 1, which houses the armature 4 in its upper portion, and the yoke in its lower portion, which houses the coil. The four corners of the partition 6 rest on the base of the contactor. Through a design that allows for tight fit between the lower surface of the partition 6 and the upper surface of the upper yoke 7, this ensures that when the electromagnetic system is energized and the armature 4 is attracted, the iron core 9, riveted to the lower yoke 10, does not move due to the mutual force. A reaction spring 5 is placed on the partition 6 and has a limiter feature for the reaction spring 5, ensuring that it does not become excessively eccentric when the contactor is actuated.

[0026] In this embodiment, the electromagnetic system uses a DC coil and a solenoid core, and is used in conjunction with the control system of the circuit board 11. When the contactor is in the initial state, Figure 2 As shown in (2a), after the electromagnetic system circuit board 11 inputs power, it is full-wave rectified by the circuit board 11, and then the DC-DC power supply unit converts the original direct input DC power or the pulsating DC power after full-wave rectification into stable low-voltage DC power to power the MCU and power output unit on the circuit board 11. At the same time, the power factor compensation unit on the circuit board 11 performs power factor compensation on the pulsating DC power after full-wave rectification. The MCU collects the voltage after full-wave rectification of the main power supply and adjusts the duty cycle of the PWM signal of the pull-in and hold according to the preset control algorithm. Finally, the MOS power output unit on the circuit board 11 adjusts the current output to the contactor coil according to the PWM signal output by the MCU. When current flows through the coil, a magnetic field is generated, and the iron core 9 generates an attractive force on the armature 4. The armature 4 first overcomes the resistance of the reaction spring 5 and begins to move until the main contacts of the contactor just touch, that is, the main contacts reach the just-closed position. Then the armature 4 overcomes the resistance of the reaction spring 5 and the contact spring and continues to move until the armature 4 and the iron core 9 are completely attracted, and the contactor completes the attraction action. At this time, the contactor is in the holding state, such as Figure 2 As shown in (2b).

[0027] During this process, since the circuit board 11 is provided with a full-wave rectification system, and the current is finally adjusted by the MOS tube power output unit on the circuit board 11 and output to the contactor coil, the contactor will not generate a large impact starting current due to the alternating current. Moreover, after full-wave rectification, the current is pulsating direct current, so that the electromagnetic system of the contactor does not have the pole surface vibration of the iron core after the current passes through zero, and the phenomenon of noise generated during the AC control contactor's attraction process is completely avoided.

[0028] In this embodiment, the circuit board 11 houses an MCU processing unit and a MOS transistor power output unit. This unit acquires the main power supply voltage through A / D conversion and adjusts the duty cycle of the PWM signals for both the closing and holding phases based on the power supply voltage and a pre-set control algorithm, thereby controlling the power consumption of the contactor during and after closing. When the electrical contactor operates, until the armature 4 and the core 9 are fully engaged, the PWM signal duty cycle is intelligently adjusted based on the full-wave rectified power supply voltage data accurately collected by the microcontroller on the circuit board 11. Because the contactor's closing process is extremely short and it spends most of its time in the holding state, a low duty cycle is set to shorten the duration of the electromagnetic control system's high-level output and lengthen the duration of the low-level output. At this point, the MOS transistor controls the current at its output drain using the voltage applied to its input gate. Rapid switching enables precise control of the contactor coil. After the armature 4 is engaged, the current flowing through the coil is significantly reduced compared to when it is closed. This significantly reduces the power consumption of the contactor while it is securely closed, directly improving the contactor's energy efficiency. This electromagnetic system design reduces the overall energy consumption of the power distribution system and the power consumption of equipment in situations where the contactor is frequently operated. Furthermore, due to the effective control of the electromagnetic system current when the contactor is engaged, the electromagnetic system of the contactor utilizes a coil with a fine wire diameter and a small number of turns. At the same control voltage level, the weight of the round copper wire wound in the coil is less than half that of a traditional DC coil, significantly reducing the overall size of the contactor.

[0029] From the perspective of the temperature rise of the electromagnetic system used in the contactor, although the circuit board can automatically adjust the output current and automatically switch to a small current after the high current is attracted, the air gap between the armature and the core is large when the contactor is attracted. Moreover, when the contactor moves to the just-closed position, the contact spring greatly increases the reaction force that the armature needs to overcome. Therefore, a large current is still required to ensure the reliable attraction of the armature. Figure 3 As shown, this embodiment adopts a semi-enclosed magnetic yoke. Through simulation calculation, the resistance of the electromagnetic coil and the magnetic force generated by the electromagnetic coil are optimized, so that the efficiency of the electromagnetic system remains basically unchanged. The electromagnetic system using the semi-enclosed magnetic yoke has better air circulation around it than the fully enclosed magnetic yoke. During the process of contactor attraction and holding, the semi-enclosed magnetic yoke will reduce the coil temperature rise caused by continuous current and effectively slow down the aging rate of the insulation material of the electromagnetic system working in a high temperature environment, directly improving the performance and life of the contactor.

[0030] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art based on the concepts of the present invention through logical analysis, reasoning, or limited experimentation based on the existing technology should be within the scope of protection defined by the claims.

Claims

1. An electromagnetic system for a contactor, characterized in that: The invention comprises a contact support (1), an armature (4), a reaction spring (5), a partition (6), a yoke, a coil skeleton (8), an iron core (9) and a circuit board (11); the armature (4) is connected to the contact support (1) through a clamping plate; the reaction spring (5) is arranged on the upper surface of the partition (6); the partition (6) is arranged between the contact support (1) and the yoke; the yoke comprises an upper yoke (7) and a lower yoke (10); the coil skeleton (8) and the iron core (9) are arranged between the upper yoke (7) and the lower yoke (10); the upper surface of the upper yoke (7) is fitted with the lower bottom surface of the partition (6); and the circuit board (11) is provided with an MCU processing unit and a MOS tube power output unit.

2. The electromagnetic system for a contactor according to claim 1, characterized in that: A moving contact (3) is provided on the contact support (1).

3. The electromagnetic system for a contactor according to claim 2, characterized in that: A contact spring (2) is provided between the moving contact (3) and the contact support (1).

4. The electromagnetic system for a contactor according to claim 1, wherein: A limiting feature for the reaction spring (5) is provided on the upper surface of the partition (6).

5. The electromagnetic system for a contactor according to claim 1, wherein: The four corners of the partition (6) are arranged on the base of the contactor.

6. The electromagnetic system for a contactor according to claim 1, wherein: The upper magnetic yoke (7) is of U-shaped design and is installed with interference fit with the lower magnetic yoke (10) through installation notches on both sides.

7. The electromagnetic system for a contactor according to claim 1, wherein: The lower magnetic yoke (10) is provided with a coil frame installation positioning hole for fixing the coil frame (8).

8. The electromagnetic system for a contactor according to claim 7, characterized in that: The coil frame (8) is positioned through the coil frame installation positioning hole and is fitted on the upper surface of the lower magnetic yoke (10).

9. The electromagnetic system for a contactor according to claim 8, characterized in that: An iron core (9) is inserted into the coil frame (8), and the iron core (9) is riveted to the upper surface of the lower magnetic yoke (10).

10. The electromagnetic system for a contactor according to claim 1, wherein: The lower bottom surface of the lower magnetic yoke (10) is arranged in the base of the contactor.

Images