Long-life direct current contactor

Abstract

The invention discloses a long-life DC contactor, and relates to the technical field of DC contactors, the long-life DC contactor comprises a base assembly and an electromagnet assembly arranged in the base assembly, a coil in the electromagnet assembly is electrified through a wiring screw of the base assembly, so that an enameled wire generates a magnetic field, and then a movable iron core and a core rod are driven to move towards the magnetic pole direction; the circuit connection between the moving plate at the top end of the core rod and the main bolt on the base assembly is realized; the moving plate is of a disc structure and is rotationally connected to the top end of the core rod. According to the long-life direct current contactor provided by the invention, in the on-off process of the moving plate and the main bolt, due to non-uniform abrasion of the surface of the contact, a contact point after electric arc burning loss gradually moves towards the inner side of the moving plate, so that the moving plate continuously rotates to adjust the position in the contact process, the abrasion is compensated, and the service life is prolonged; and the electric service life is more than 4-6 times of that of the conventional similar contactor.

Description

Technical Field

[0001] This invention relates to the field of DC contactor technology, and more specifically to a long-life DC contactor. Background Technology

[0002] With the continuous advancement of technology and market development, DC contactors have been widely used in many fields, especially in the clean energy sector, where their application is increasing daily. However, traditional DC contactors have gradually revealed some shortcomings in practical use, making it difficult to meet today's diverse and demanding application requirements.

[0003] During the startup and driving of a DC motor, the current is typically high, causing significant burn-out of the contacts. Traditional DC contactors mostly employ a bridging design, resulting in limited contact compensation margin after arcing and a relatively short service life under heavy load and rapid burn-out conditions. This not only increases maintenance costs but also affects the normal operation of the equipment.

[0004] In fields such as engineering vehicles, actual operating conditions are complex, with high humidity and dust levels. Most low-voltage DC contactors on the market are not completely waterproof or dustproof, and are also bulky. In low-temperature environments, the inside of the DC contactor is prone to icing, preventing normal operation; in high-humidity environments, it is susceptible to moisture absorption, leading to decreased insulation performance; in environments with high levels of dust and foreign matter, dust and foreign objects can easily fall into the product, causing jamming and non-conductivity problems, severely affecting the contactor's reliability and lifespan.

[0005] Furthermore, for applications such as small electric forklifts and DC hydraulic power systems, frequent starts place high demands on the breaking capacity and sensitivity of the contactor. Traditional general-purpose DC contactors have a slow response speed in these situations, resulting in poor performance and difficulty in meeting the requirements for rapid switching.

[0006] In summary, existing DC contactors suffer from numerous problems in terms of service life, environmental adaptability, and dynamic performance, severely limiting their application scope and market development. Therefore, developing a new type of long-life DC contactor to improve product performance and expand its application range has become an urgent problem to be solved in the current market. Summary of the Invention

[0007] In view of this, the present invention provides a long-life DC contactor, which aims to solve the above-mentioned technical problems.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A long-life DC contactor includes a base assembly and an electromagnet assembly disposed within the base assembly. The coil in the electromagnet assembly is energized by the wiring screw of the base assembly, causing the enameled wire to generate a magnetic field, which in turn drives the moving iron core and the core rod to move in the direction of the magnetic pole, thereby connecting the moving piece at the top of the core rod with the main bolt on the base assembly.

[0010] The moving plate has a disc structure and is rotatably connected to the top of the core rod. During the switching process between the moving plate and the main bolt, due to uneven wear on the contact surface, the contact point after arc burning will gradually move towards the inside of the moving plate. This causes the moving plate to continuously rotate and adjust its position during the contact process to compensate for wear and extend its service life.

[0011] Through the above technical solution, the moving piece of the long-life DC contactor provided by the present invention adopts a disc structure and is rotatably connected to the top of the core rod. It can continuously rotate and adjust its position during the switching process as the contact surface wears unevenly, to compensate for the wear caused by arc burning, effectively extend the service life, and make the electrical life reach 4 to 6 times or more than that of traditional contactors of the same type.

[0012] Preferably, in the aforementioned long-life DC contactor, the base assembly includes a base housing with a bottom opening for inserting the electromagnet assembly. The top of the base housing has a set of wiring screws for energizing the enameled wire and a set of main bolts for connecting to the moving contact. The bottom opening of the base housing facilitates the insertion of the electromagnet assembly, and the reasonable layout of the wiring screws and main bolts at the top is conducive to realizing coil energization and circuit connection between the moving contact and the main bolts, providing a basic structural guarantee for the overall assembly and electrical connection of the contactor.

[0013] Preferably, in the aforementioned long-life DC contactor, the main bolt and the terminal screw are integrally formed during the injection molding process of the base housing. Integrating the main bolt and terminal screw during the injection molding process of the base housing reduces the number of parts and assembly steps, improves production efficiency, lowers production costs, and simultaneously enhances the integrity and reliability of the base assembly, ensuring the stability of the electrical connection.

[0014] Preferably, in the above-mentioned long-life DC contactor, a guide groove is provided at the center of the top of the base housing, and a return spring is provided in the guide groove. The two ends of the return spring abut against the bottom of the guide groove and the top of the core rod. This provides a stable restoring force for the core rod and the moving piece, ensuring that the moving piece quickly and accurately separates from the main bolt after power is cut off, thereby improving the contactor's breaking capacity and operating sensitivity.

[0015] Preferably, in the above-mentioned long-life DC contactor, a mounting base plate is fixedly connected to the bottom opening of the base housing by rivets, and a mounting plate is integrally formed on one side of the mounting base plate. This structural design makes the contactor installation more convenient and stable, can adapt to different installation scenarios and needs, and improves the versatility and practicality of the product.

[0016] Preferably, in the above-mentioned long-life DC contactor, the moving iron core is riveted and fixed to the core rod. A coil frame is sleeved on the outside of the moving iron core, and the enameled wire is evenly wound on the coil frame. An upper magnetic plate and a lower magnetic plate are fixed to the top and bottom of the coil frame, respectively. The magnetic poles are riveted and fixed to the upper magnetic plate. A magnetic ring fixed to the outside of the coil frame connects the upper and lower magnetic plates, forming a complete closure of the internal and external magnetic circuits. The lower magnetic plate is connected to the magnetic ring and fits against the bottom of the coil of the enameled wire. The moving iron core is riveted and fixed to the core rod, ensuring a firm and reliable connection that can withstand greater electromagnetic forces and guaranteeing stable transmission between the moving iron core and the core rod. The magnetic ring fixed to the outside of the coil frame connects the upper and lower magnetic plates, forming a complete closure of the internal and external magnetic circuits, improving the magnetic permeability of the magnetic circuit and enhancing the electromagnetic attraction force. This increases the electromagnetic attraction force by more than 40% compared to traditional designs, providing a strong guarantee for the contactor's breaking capacity and sensitivity. The lower magnetic plate is connected to the magnetic ring and fits against the bottom of the enameled wire coil, which helps to reduce magnetic resistance and further improve the efficiency of the magnetic circuit.

[0017] Preferably, in the aforementioned long-life DC contactor, the top of the moving iron core forms a frustum-shaped structure, and the bottom of the magnetic pole has a conical hole corresponding to the frustum-shaped structure, so that the moving iron core and the magnetic pole form a conical mating surface. This conical mating increases the contact area between the moving iron core and the magnetic pole, improves the efficiency and stability of magnetic force transmission, and also facilitates the centering and guiding of the moving iron core, ensuring the accuracy and reliability of the moving iron core during movement, further enhancing the electromagnetic attraction and the contactor's operating performance.

[0018] Preferably, in the above-mentioned long-life DC contactor, a fixing groove is formed on the edge of the coil frame, and a connecting piece is inserted into the fixing groove. The connecting piece is wound and welded to the beginning and end of the enameled wire. The connecting piece corresponds to the terminal screw, and a conductive spring is connected between the connecting piece and the terminal screw. This connection method not only ensures a good electrical connection between the coil and the terminal screw, but also provides a certain degree of elasticity compensation from the conductive spring, enhancing the reliability of the connection. It also helps to reduce contact resistance, improve electrical performance, and has a compact structure, facilitating assembly.

[0019] Preferably, in the aforementioned long-life DC contactor, the side wall of the core rod above the magnetic pole has a variable diameter section with an increased diameter. A contact spring, sleeved on the core rod, is provided between the variable diameter section and the moving plate. Insulating washers are provided at both ends of the contact spring. This design provides suitable pressure to the moving plate, ensuring good contact pressure between the moving plate and the main bolt. At the same time, the insulating washers prevent short circuits, ensuring the stability and safety of electrical performance.

[0020] Preferably, in the aforementioned long-life DC contactor, the top end of the core rod restricts the axial displacement of the moving piece via an open retaining ring, and the bottom end of the core rod is riveted to a cap plate located at the bottom end of the moving iron core. The open retaining ring at the top end of the core rod restricts the axial displacement of the moving piece, effectively preventing excessive displacement or detachment during operation and ensuring stable operation. The cap plate riveted to the bottom end of the core rod reduces magnetic leakage, concentrates electromagnetic attraction, further improves the efficiency and performance of the electromagnetic system, and also enhances the connection strength between the moving iron core and the core rod.

[0021] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a long-life DC contactor, which has the following beneficial effects:

[0022] 1. Long-life contact system: The moving piece adopts a disc structure and is rotatably connected to the top of the core rod. It can continuously rotate and adjust its position during the switching process as the contact surface wears unevenly. This design effectively extends the service life by compensating for wear caused by arc burning, making the electrical life 4 to 6 times longer than that of traditional contactors of the same type.

[0023] 2. Enhanced Electromagnetic System: The conical magnetic circuit structure design, combined with the conical mating surface between the moving iron core and the magnetic poles, significantly increases the magnetic attraction area and improves the electromagnetic attraction force. Under the same volume conditions, the electromagnetic attraction force is increased by more than 40% compared to traditional designs, thereby improving the product's breaking capacity and sensitivity.

[0024] 3. Compact structural design: The main bolts and wiring screws are integrally molded during the injection molding process of the base housing, reducing the number of parts and assembly steps, improving production efficiency, and lowering production costs. At the same time, it enhances the integrity and reliability of the base assembly, ensuring the stability of the electrical connection.

[0025] 4. Excellent sealing and protection performance: The bottom opening of the base shell is fixedly connected to the mounting base plate by rivets, and the mounting base plate has an integrally formed mounting plate on one side. This structural design makes the installation of the contactor more convenient and stable, and can adapt to different installation scenarios and needs, improving the versatility and practicality of the product.

[0026] 5. Optimized Magnetic Circuit Closure Structure: The magnetic ring fixed on the outside of the coil frame connects the upper and lower magnetic plates, forming a complete closure of the inner and outer magnetic circuits. This improves the magnetic permeability of the magnetic circuit and enhances the electromagnetic attraction. The lower magnetic plate is connected to the magnetic ring and fits against the bottom of the enameled wire coil, which helps reduce magnetic resistance and further improves the efficiency of the magnetic circuit.

[0027] 6. Stable electrical connection: A connecting piece is inserted into the fixing groove on the edge of the coil frame. The connecting piece is wound and welded to the beginning and end of the enameled wire, and a conductive spring is connected between it and the terminal screw. This connection method not only ensures a good electrical connection between the coil and the terminal screw, but also provides a certain elasticity compensation through the conductive spring, which enhances the reliability of the connection. At the same time, it also helps to reduce contact resistance and improve electrical performance.

[0028] 7. Reasonable pressure distribution: The side wall of the core rod above the magnetic pole has a variable diameter section with an increased diameter. A contact spring is installed between the variable diameter section and the moving plate, and insulating washers are installed at both ends of the contact spring. This design can provide appropriate pressure to the moving plate, ensuring good contact pressure between the moving plate and the main bolt. At the same time, the insulating washers can prevent short circuits and ensure the stability and safety of electrical performance.

[0029] 8. Prevention of excessive displacement and magnetic leakage: The axial displacement of the moving piece is restricted by an open retaining ring at the top of the core rod, which effectively prevents excessive displacement or detachment of the moving piece during operation, ensuring stable operation of the moving piece. A cap plate located at the bottom of the moving iron core is riveted to the bottom of the core rod. The cap plate can reduce magnetic leakage, make the electromagnetic attraction more concentrated, further improve the efficiency and performance of the electromagnetic system, and also help to enhance the connection strength between the moving iron core and the core rod. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0031] Figure 1 The attached figure is a schematic diagram of a half-section of the long-life DC contactor provided by the present invention, cut along the plane where the wiring screw is located.

[0032] Figure 2 The attached figure is provided by the present invention. Figure 1 A cross-sectional view at an angle;

[0033] Figure 3 The attached figure is a schematic diagram of a half-section of the long-life DC contactor provided by the present invention, cut along the plane where the main bolt is located.

[0034] Figure 4 The attached figure is provided by the present invention. Figure 3 A cross-sectional view at an angle;

[0035] Figure 5 The attached figure is a schematic diagram of the external structure of the long-life DC contactor provided by the present invention.

[0036] in:

[0037] 10-Base assembly;

[0038] 101-Connecting screw; 102-Main bolt; 103-Base housing; 1031-Guide groove; 104-Rivet;

[0039] 20 - Electromagnet assembly;

[0040] 201-Enameled wire; 202-Moving iron core; 2021-Frustum structure; 203-Core rod; 2031-Variable diameter section; 204-Magnetic pole; 2041-Conical hole; 205-Moving plate; 206-Return spring; 207-Coil frame; 2071-Fixing slot; 208-Upper magnetic guide plate; 209-Lower magnetic guide plate; 210-Magnetic ring; 211-Connecting piece; 212-Conductive spring; 213-Contact spring; 214-Insulating washer; 215-Open retaining ring; 216-Cap plate;

[0041] 30 - Install base plate;

[0042] 301 - Mounting plate. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] See appendix Figure 1 and attached Figure 2 This invention discloses a long-life DC contactor, including a base assembly 10 and an electromagnet assembly 20 disposed within the base assembly 10. The coil in the electromagnet assembly 20 is energized via a wiring screw 101 in the base assembly 10, causing the enameled wire 201 to generate a magnetic field. This magnetic field drives the moving iron core 202 and the core rod 203 to move towards the magnetic pole 204, thus connecting the moving piece 205 at the top of the core rod 203 with the main bolt 102 on the base assembly 10. The invention is characterized by:

[0045] The moving piece 205 has a disc structure and is rotatably connected to the top of the core rod 203. During the switching process between the moving piece 205 and the main bolt 102, due to uneven wear on the contact surface, the contact point after the arc burns will gradually move towards the inside of the moving piece 205. This causes the moving piece 205 to continuously rotate and adjust its position during the contact process to compensate for wear and extend its service life.

[0046] To further optimize the above technical solution, the base assembly 10 includes a base housing 103 with a bottom opening for inserting the electromagnet assembly 20. The top of the base housing 103 has a set of wiring screws 101 for energizing the enameled wire 201 and a set of main bolts 102 for connecting to the moving piece 205.

[0047] To further optimize the above technical solution, the main bolt 102 and the wiring screw 101 are integrally formed during the injection molding process of the base housing 103.

[0048] To further optimize the above technical solution, a guide groove 1031 is provided at the top center of the base shell 103. A return spring 206 is provided in the guide groove 1031, and the two ends of the return spring 206 abut against the bottom of the guide groove 1031 and the top of the core rod 203.

[0049] See appendix Figure 5 The bottom opening of the base shell 103 is fixedly connected to the mounting base plate 30 by rivets 104, and the mounting base plate 30 has an integrally formed mounting plate 301 on one side.

[0050] To further optimize the above technical solution, the moving iron core 202 is riveted and fixed on the core rod 203. A coil frame 207 is sleeved on the outside of the moving iron core 202. The enameled wire 201 is evenly wound on the coil frame 207. An upper magnetic plate 208 and a lower magnetic plate 209 are fixed at the top and bottom of the coil frame 207, respectively. The magnetic pole 204 is riveted and fixed to the upper magnetic plate 208. A magnetic ring 210 fixed on the outside of the coil frame 207 connects the upper magnetic plate 208 and the lower magnetic plate 209 to form a complete closure of the inner and outer magnetic circuits. The lower magnetic plate 209 is connected to the magnetic ring 210 and fits against the bottom of the coil of the enameled wire 201.

[0051] See appendix Figure 3 and attached Figure 4 The top of the moving iron core 202 forms a frustum structure 2021, and the bottom of the magnetic pole 204 has a conical hole 2041 corresponding to the frustum structure 2021, so that the moving iron core 202 and the magnetic pole 204 form a conical mating surface.

[0052] To further optimize the above technical solution, a fixing groove 2071 is provided on the edge of the coil frame 207. A connecting piece 211 is inserted into the fixing groove 2071. The connecting piece 211 is wound and welded to the beginning and end of the enameled wire 201. The connecting piece 211 corresponds to the wiring screw 101, and a conductive spring 212 is connected between the connecting piece 211 and the wiring screw 101.

[0053] To further optimize the above technical solution, the side wall of the core rod 203 above the magnetic pole 204 has a variable diameter section 2031 with an increased diameter. A contact spring 213 is provided between the variable diameter section 2031 and the moving plate 205 and is sleeved on the core rod 203. Insulating washers 214 are provided at both ends of the contact spring 213.

[0054] To further optimize the above technical solution, the top of the core rod 203 is restricted to limit the axial displacement of the moving piece 205 by an open retaining ring 215, and the bottom end of the core rod 203 is riveted to a cap piece 216 located at the bottom end of the moving iron core 202.

[0055] The long-life DC contactor provided in this embodiment achieves circuit connection and disconnection based on electromagnetic principles. Its core lies in the cooperation between the electromagnet assembly 20 and the moving piece 205. When the enameled wire 201 is energized, a magnetic field is generated, attracting the moving iron core 202 and the core rod 203 to move towards the magnetic pole 204, thereby causing the moving piece 205 to contact the main bolt 102, forming a circuit path. After de-energization, the magnetic field disappears, and under the action of the return spring 206 and the contact spring 213, the moving iron core 202 resets, and the moving piece 205 separates from the main bolt 102, cutting off the circuit. This design achieves circuit control by driving the contact action through electromagnetic force.

[0056] Work process:

[0057] 1. Circuit Connection Process: When the coil is energized, the enameled wire 201 generates a magnetic field. Under the influence of this magnetic field, the moving iron core 202 overcomes the resistance of the return spring 206 and moves towards the magnetic pole 204. The moving iron core 202 drives the moving plate 205 to move upward via the core rod 203. The moving plate 205 contacts the main bolt 102, completing the circuit connection and achieving the purpose of controlling a large current with a small current.

[0058] 2. Disconnection process: When the coil is de-energized, the magnetic field disappears, and the moving iron core 202 resets under the action of the return spring 206 and the contact spring 213. The moving iron core 202 drives the moving plate 205 to separate from the main bolt 102 through the core rod 203. The circuit is broken.

[0059] 3. Arc Loss Compensation Process: During the switching process, arc loss causes gradual wear on the contact surface. The moving piece 205 gradually rotates as the contact wears down, starting from the center of the stationary terminal and rotating inwards one revolution at a time. This rotation effectively increases the travel compensation after arc loss. Calculated according to pi, the increased compensation travel margin is at least 6 times that of traditional bridging designs, thereby extending service life.

[0060] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0061] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A long-life DC contactor, comprising a base assembly (10) and an electromagnet assembly (20) disposed within the base assembly (10), wherein the coil in the electromagnet assembly (20) is energized by a wiring screw (101) of the base assembly (10), causing the enameled wire (201) to generate a magnetic field, thereby driving the moving iron core (202) and the core rod (203) to move towards the magnetic pole (204), thereby achieving circuit connection between the moving piece (205) at the top of the core rod (203) and the main bolt (102) on the base assembly (10); characterized in that: The movable piece (205) has a disc structure and is rotatably connected to the top of the core rod (203). During the switching process between the movable piece (205) and the main bolt (102), due to uneven wear on the contact surface, the contact point after arc burn-out will gradually move towards the inside of the movable piece (205), thereby causing the movable piece (205) to continuously rotate and adjust its position during the contact process to compensate for wear and extend its service life.

2. The long-life DC contactor according to claim 1, characterized in that, The base assembly (10) includes a base housing (103) with a bottom opening for housing the electromagnet assembly (20), and a set of wiring screws (101) for energizing the enameled wire (201) and a set of main bolts (102) for connecting to the moving piece (205) at the top of the base housing (103).

3. A long-life DC contactor according to claim 2, characterized in that, The main bolt (102) and the wiring screw (101) are integrally formed during the injection molding process of the base shell (103).

4. A long-life DC contactor according to claim 2, characterized in that, The base housing (103) has a guide groove (1031) at the top center, and a return spring (206) is provided in the guide groove (1031). The two ends of the return spring (206) abut against the bottom of the guide groove (1031) and the top of the core rod (203).

5. A long-life DC contactor according to claim 2, characterized in that, The bottom opening of the base shell (103) is fixedly connected to the mounting base plate (30) by rivets (104), and the mounting base plate (301) is integrally formed on one side of the mounting base plate (30).

6. A long-life DC contactor according to claim 1, characterized in that, The moving iron core (202) is riveted and fixed to the core rod (203). A coil frame (207) is sleeved on the outside of the moving iron core (202). The enameled wire (201) is evenly wound on the coil frame (207). An upper magnetic plate (208) and a lower magnetic plate (209) are fixed at the top and bottom of the coil frame (207), respectively. The magnetic pole (204) is riveted and fixed to the upper magnetic plate (208). A magnetic ring (210) fixed on the outside of the coil frame (207) connects the upper magnetic plate (208) and the lower magnetic plate (209) to form a complete closure of the inner and outer magnetic circuits. The lower magnetic plate (209) is connected to the magnetic ring (210) and fits against the bottom of the coil of the enameled wire (201).

7. A long-life DC contactor according to claim 5, characterized in that, The top of the moving iron core (202) forms a frustum structure (2021), and the bottom of the magnetic pole (204) has a conical hole (2041) corresponding to the frustum structure (2021), so that the moving iron core (202) and the magnetic pole (204) form a conical mating surface.

8. A long-life DC contactor according to claim 5, characterized in that, The coil frame (207) has a fixing groove (2071) on its edge. A connecting piece (211) is inserted into the fixing groove (2071). The connecting piece (211) is wound and welded to the beginning and end of the enameled wire (201). The connecting piece (211) corresponds to the wiring screw (101), and a conductive spring (212) is connected between the connecting piece (211) and the wiring screw (101).

9. A long-life DC contactor according to claim 1, characterized in that, The core rod (203) has a variable diameter section (2031) with an increased diameter on the side wall above the magnetic pole (204). A contact spring (213) is provided between the variable diameter section (2031) and the moving plate (205) and sleeved on the core rod (203). Insulating washers (214) are provided at both ends of the contact spring (213).

10. A long-life DC contactor according to claim 1, characterized in that, The top end of the core rod (203) is restricted by an open retaining ring (215) to limit the axial displacement of the moving piece (205), and the bottom end of the core rod (203) is riveted to a cap piece (216) located at the bottom end of the moving iron core (202).

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