Contact system of switch

Abstract

The invention provides a contact system of a switch. The contact system comprises a moving contact assembly, a static contact assembly and an insulating shell used for arranging the moving contact assembly and the static contact assembly. One end of the moving contact assembly is a rotating fulcrum, the other end of the moving contact assembly is provided with a moving contact, the moving contact assembly can rotate around the rotating fulcrum to make contact with or be separated from the static contact assembly, a driving fulcrum is arranged in the middle of the moving contact assembly, and a magnetic armature is arranged in front of the moving contact. A U-shaped magnet yoke is arranged on the lower conductor corresponding to the magnetic armature; when the movable contact is in contact with the static contact, a gap of at least 0.2 mm is formed between the magnetic armature and the two end faces of the U-shaped magnet yoke, and when the movable contact is separated from the static contact, an acute angle is formed between the magnetic armature and the two end faces of the U-shaped magnet yoke.

Description

Technical Field

[0001] The invention relates to the technical field of low-voltage electrical appliances, and in particular to a contact system of a switch. Background Art

[0002] The rotating clap contact system structure will generate an arc between the contacts when the contacts disconnect a large current. When an abnormal situation such as a short circuit occurs, the arc generated exceeds the arc extinguishing capacity of the contacts and will cause the contacts to burn out.

[0003] The rotating clapping contact system structure has the characteristics of simple structure and reliable operation, and is widely used in low-voltage electrical appliances such as relays, circuit breakers, and contactors. However, due to the existence of contraction current at the connection point between the moving and static contacts in the structure, a repulsive force of Holm force is generated between the moving and static contacts. When the current in the circuit is extremely large or a short-circuit current occurs, the Holm force is greater than the contact pressure, and the moving and static contacts will be repelled, causing a virtual contact between the repelled contacts, causing the contact system to increase sharply, causing the electrical appliance to burn; arcs will also be generated between the repelled contacts. When the arc is too large, the contacts will be burned, bonded, ablated, or even exploded, posing a safety hazard. Due to the limitation of the input driving force, it cannot be solved by simply increasing the contact pressure.

[0004] The existence of the above problems limits the application scope of low-voltage electrical products. Summary of the invention

[0005] Based on the above background, the present invention provides a contact system for a switch, aiming to overcome the defects existing in the above-mentioned prior art. The present invention has a contact system that has both arc striking and arc extinguishing functions and increases contact pressure, and has low cost. It can effectively improve the dynamic stability of the switch, thereby achieving higher short-time tolerance and good arc striking and arc extinguishing capabilities, and can effectively overcome at least one of the above-mentioned problems.

[0006] The technical solution of the present invention is as follows:

[0007] On the one hand, the present invention provides a contact system of a switch, which contact system at least includes: a moving contact assembly, a stationary contact assembly, and an insulating shell for arranging the moving contact assembly and the stationary contact assembly; one end of the moving contact assembly is a rotating fulcrum and the other end is provided with a moving contact, the moving contact assembly can rotate around the rotating fulcrum to contact or separate from the stationary contact assembly, a driving fulcrum is provided in the middle of the moving contact assembly, a magnetic armature is provided in front of the moving contact, the stationary contact assembly at least includes a conductor and a stationary contact, and a U-shaped yoke is provided on the conductor below corresponding to the magnetic armature; when the moving contact contacts the stationary contact, a gap of at least 0.2 mm is provided between the magnetic armature and the two end surfaces of the U-shaped yoke, and when the moving contact separates from the stationary contact, an acute angle is provided between the magnetic armature and the two end surfaces of the U-shaped yoke.

[0008] In the above embodiment, the static contact assembly is fixed to the insulating housing, and the moving contact assembly can rotate around the rotating fulcrum under the drive of external force, so as to form the contact and separation operation of the moving and static contacts. A magnetic armature is arranged in front of the moving contact, and cooperates with the U-shaped magnetic yoke correspondingly arranged on the static contact assembly. When the moving and static contacts are closed and current flows through, the U-shaped magnetic yoke is magnetized to generate magnetic poles, forming a closed magnetic circuit, attracting the magnetic armature to generate suction, which is transmitted to the contacts to become contact pressure, compensating for the Holm force generated between the contacts due to the contraction current, and preventing the Holm force generated between the contacts under high current or short-circuit current from repelling the moving and static contacts to generate arcs, and causing the contacts to fail due to welding, burning or even explosion. When the moving and static contacts disconnect a large current, an arc will appear. Under the action of the magnetic field of the U-shaped yoke, the arc will deviate to the acute-angle opening between the magnetic armature and the two end surfaces of the U-shaped yoke. The arc root moves to the magnetic armature and the U-shaped yoke and is elongated and extinguished, or is introduced into the arc-extinguishing grid set in front of the opening and extinguished, thereby protecting the contacts from reliable disconnection.

[0009] Wear is inevitable when the moving and static contacts are working. The worn contacts will reduce the gap between the magnetic armature and the U-shaped yoke when they are closed. Excessive wear of the contacts may cause the magnetic armature to contact before the moving and static contacts, resulting in a failure to contact or unreliable contact. Unreliable contact caused by contact wear is not compensated. To ensure reliable contact within the life cycle of the contacts, a gap of at least 0.2 mm is set between the magnetic armature and the two end faces of the U-shaped yoke when the contacts are closed.

[0010] In some embodiments, a soft wire is provided on the moving contact or at a position near the moving contact.

[0011] In the above embodiment, the flexible wire is arranged on the moving contact or on the moving contact assembly near the moving contact, which can expand the moving contact's range of motion and reduce the influence of the moving contact assembly's reaction force on the driving force. In addition, the structure of the moving contact assembly other than the moving contact does not need to be conductive or only needs to be partially conductive, and a material with a slightly larger resistivity and a lower price can be selected, which can effectively reduce costs and has strong practicality.

[0012] In some embodiments, a soft wire is provided at or near the rotation fulcrum of the moving contact assembly.

[0013] The setting position of the conductive soft wire is not limited and can be set on the moving contact assembly. When it is set at the rotation fulcrum of the moving contact assembly or at a position near it, the influence of the soft wire deflection on the rotation of the moving contact assembly can be effectively reduced, and the current flows from the soft wire position of the moving contact assembly to the moving contact position. At this time, an auxiliary U-shaped magnetic yoke and a magnetic armature can be set on the moving contact assembly to generate an auxiliary compensation force.

[0014] In some embodiments, a second U-shaped magnetic yoke is disposed in front of and / or behind the driving fulcrum.

[0015] In the above embodiment, when the contacts are closed, the second U-shaped yoke is magnetized by the current flowing through the moving contact assembly to generate magnetic poles, which attract the matching armature to generate suction force.

[0016] In some embodiments, a second armature is provided in a gap-shaped manner on the insulating shell below the second U-shaped magnetic yoke.

[0017] In the above embodiment, the magnetized second U-shaped yoke generates suction with the second armature fixed to the housing, and the suction is applied to the moving contact through the moving contact assembly, becoming contact pressure, providing compensation force for the contact, and preventing the moving contact from being repelled by the Holm force. There is a gap between the second magnet and the second U-shaped yoke to ensure that after the moving contact and the static contact are worn and thinned during the life cycle, the contact between the moving contact and the static contact will not be affected due to the interference between the second magnet and the second U-shaped yoke.

[0018] In some embodiments, the second U-shaped magnetic yokes are provided in at least one pair.

[0019] In the above embodiment, the second U-shaped magnetic yokes are arranged in pairs to provide auxiliary compensation force, and more arrangements can increase the compensation force.

[0020] In some embodiments, at least one first connecting terminal and one second connecting terminal are disposed on the insulating housing.

[0021] In the above embodiment, at least one first wiring terminal and one second wiring terminal are arranged on the housing for external wiring.

[0022] In some embodiments, the flexible wire is directly or indirectly connected to the first terminal.

[0023] In the above embodiment, one end of the soft wire is connected to the moving contact assembly, and the other end is directly or indirectly connected to the first terminal for external wiring. The connection method can be but is not limited to welding, riveting, clamping, screw fixing, etc.

[0024] In some embodiments, the static contact assembly is connected to or integrated with the second terminal.

[0025] In the above embodiment, at least the second terminal of the stationary contact assembly can be either a continuation of the conductor of the stationary contact assembly or a component connected to the conductor of the stationary contact assembly. The connection can be but is not limited to welding, riveting, clamping, screw fixing, etc. The two schemes can be selected and used according to the specific usage.

[0026] In some embodiments, at least two arc-extinguishing grids are disposed in front of the magnetic armature and the U-shaped magnetic yoke.

[0027] In the above embodiment, the magnetic armature in front of the moving contact serves as an arc striking angle to guide the arc into the arc extinguishing grid to extinguish the arc, thereby improving the arc extinguishing capability of the electrical appliance using the contact system and increasing its electrical life.

[0028] In some embodiments, the contact system is driven by an electromagnetic system or a motor reduction system.

[0029] In the above embodiments, the driving source of the contact system can be an electromagnetic system or a motor reduction system. The two driving modes can be selected according to the electrical conditions of the contactor system.

[0030] The beneficial effects of the present invention are as follows:

[0031] 1. By arranging a magnetic armature in front of the moving contact and a corresponding U-shaped magnetic yoke arranged on the conductor of the stationary contact, a Lorentz force is generated when the moving contact assembly and the stationary contact assembly are disconnected, which can effectively introduce the arc into the arc extinguishing chamber and extinguish the arc quickly in the arc extinguishing chamber, thereby protecting the moving contacts and stationary contacts of the contact system and improving the electrical life of the contact system.

[0032] 2. When the moving contact and the static contact are in contact, the U-shaped yoke and the magnetic armature form a closed magnetic circuit, which attracts the U-shaped yoke and the magnetic armature to prevent them from being repelled by large current, thereby improving the short-term tolerance of the contacts.

[0033] 3. The present invention provides a rotary snap-on electrical contact system that has both arc striking and arc extinguishing functions and increases contact pressure. It has a simple structure, saves materials and space, and is particularly suitable for use in small-volume, compact electrical products. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A schematic diagram of the contact system structure of a switch disclosed in the first embodiment of the present invention;

[0036] Figure 2 It is a structural schematic diagram of a moving contact assembly disclosed in the first embodiment of the present invention;

[0037] Figure 3 It is a structural schematic diagram of a static contact assembly disclosed in the first embodiment of the present invention;

[0038] Figure 4 A schematic diagram of the contact system current and magnetic field direction of the switch disclosed in the first embodiment of the present invention;

[0039] Figure 5 for Figure 1 Another schematic diagram of the current direction and the magnetic field direction in the contact system of the switch disclosed in the first embodiment;

[0040] Figure 6 A schematic diagram of a flexible wire connected to a moving contact assembly in a contact system of a switch disclosed in the first embodiment;

[0041] Figure 7 A schematic diagram of a flexible wire connected to a moving contact assembly in a contact system of a switch disclosed in the first embodiment;

[0042] Figure 8 A schematic diagram of increasing contact pressure on a flexible wire in a contact system of a switch disclosed in the first embodiment;

[0043] Fig. 9 A schematic diagram of a contact system of a switch disclosed in the first embodiment showing that the contact is opened and the armature and the U-shaped yoke are at an acute angle;

[0044] Fig.10 A schematic diagram of the contact system structure of a switch disclosed in the second embodiment;

[0045] Fig.11 This is a schematic diagram of the current direction and magnetic field direction of the contact system of the switch disclosed in the second embodiment. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical scheme and advantages of the implementation of the present invention clearer, the technical scheme in the embodiment of the present invention will be described in more detail below in conjunction with the drawings in the embodiment of the present invention. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of the present invention, not all of the embodiments.

[0047] The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be construed as limiting the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0048] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0049] First embodiment:

[0050] like Figures 1 to 5 As shown, this embodiment provides a contact system of a switch. Specifically, as Figure 1 As shown, the contact system at least includes a moving contact assembly 100, a stationary contact assembly 200 and an insulating housing 700. Figure 2 As shown, one end of the moving contact assembly 100 is a rotating fulcrum 1001, and the other end is a moving contact 103. A magnetic armature 102 is arranged in front of the moving contact 103; Figure 3 As shown, the static contact 200 assembly includes a conductor 201, a static contact 203 and a U-shaped yoke 202 arranged on the conductor 201; wherein the U-shaped yoke 202 is arranged corresponding to the magnetic armature 102. A driving fulcrum 1002 is arranged in the middle of the moving contact assembly 100, and an external force drives the moving contact assembly 100 to rotate around the rotating fulcrum 1001 through the driving fulcrum 1002 to contact or separate from the static contact assembly 200.

[0051] In this embodiment, the tail of the moving contact 103 is used to rivet the magnetic armature 102 to form the moving contact assembly 100. After riveting, the magnetic armature 102 extends outward from the moving contact 103. A soft wire 800 is welded to the tail of the moving contact 103, and the other end of the soft wire 800 is welded to the terminal 3001. The stationary contact 203 of the stationary contact assembly 200 is welded to the conductor 201; the U-shaped yoke 202 is clamped on the conductor 201 and fixed together in the insulating housing 700, and the end of the conductor 201 away from the stationary contact 203 is the second terminal 3002.

[0052] like Figure 4 As shown, when the moving contact assembly 100 is in contact with the stationary contact assembly 200, there is a gap δ between the two end surfaces of the U-shaped magnetic yoke (202) and the magnetic armature 102, δ≥0.2mm, to ensure that after the moving contact 103 and the stationary contact 203 are worn and thinned during the life cycle, the contact between the moving contact 103 and the stationary contact 203 will not be affected by the conflict between the magnetic armature 102 and the U-shaped magnetic yoke 202. When the moving contact 103 and the stationary contact 203 are separated, the magnetic armature 102 and the two end surfaces of the U-shaped magnetic yoke 202 form an acute angle.

[0053] It should be noted that the assembly of the moving contact assembly 100 can be riveted or welded, and the magnetic armature 102 can be riveted in the above-mentioned manner, or fixed by clamping, welding, riveting or screwing, as long as the purpose of rigid connection with the moving contact assembly 100 is achieved. The connection of the static contact 203 can be welded or riveted. The installation of the U-shaped yoke 202 can be fixed in the above-mentioned installation manner, or by clamping, welding, riveting or screwing, or by fixing it using the surrounding structure of the product. Regardless of whether it is fixed by clamping, welding, riveting or screwing, or by fixing it using the surrounding structure of the product, as long as it cooperates with the magnetic armature 102 to form a closed magnetic circuit and is fixed to the applied structure. The connection between the soft wire 800 and the static contact assembly 200 and the first terminal 3001 is not limited to welding, and can also be one or more of the above-mentioned connection methods.

[0054] like Figure 5As shown, when the moving contact assembly 100 and the stationary contact assembly 200 form a contact system, the moving contact 103 cooperates with the stationary contact 203 to form a reliable contact or separation. The magnetic armature 102 cooperates with the U-shaped yoke 202. When the moving contact 103 and the stationary contact 203 are closed, the U-shaped yoke 202 and the magnetic armature 102 form a complete magnetic induction structure, and the magnetic armature 102 and the U-shaped yoke 202 form a closed magnetic circuit with an air gap δ. When the current I flows through the stationary contact assembly, the U-shaped yoke 202 is magnetized to form a magnetic pole, and the magnetic pole attracts the magnetic armature 102 to generate suction; the magnitude of the suction force is related to the current I flowing through the conductor 201, the magnetic pole gap δ, the magnetic pole area, and the shape. The larger the current I, the smaller the magnetic pole gap δ, and the larger the magnetic pole area, the greater the suction force. The ideal suction force can be achieved by adjusting these parameters. Therefore, when the current I flowing through the circuit is the rated value or a smaller value, the suction force generated by the magnetic poles of the yoke is smaller, and the Holm force between the contacts is also smaller at this time, which will not affect the closing and breaking operating force of the contacts. When the current I flowing through the circuit is a maximum or short-circuit current, the Holm force between the contacts is larger, and the suction force generated between the magnetic poles of the U-shaped yoke 202 is also larger. At this time, if the Holm force matches the magnetic pole suction force of the U-shaped yoke 202 and offsets each other, the contact will not be disconnected due to the Holm force, and because the magnetic suction force and the Holm force offset each other, the contact pressure remains basically unchanged, and will not affect the closing and breaking operating force of the contact. In order to match the magnetic pole suction force of the U-shaped yoke 202 with the Holm force, the magnetic pole area and the magnetic pole gap δ can be adjusted to achieve force matching.

[0055] When the moving contact 103 and the stationary contact 203 interrupt the current, an arc will be generated, the magnetic poles of the magnetic armature 102 and the U-shaped magnetic yoke 202 will be separated, and the magnetic field will be distributed between the contacts. The arc will be guided to the magnetic armature 102 by the Lorentz force and will be elongated. The arc root will move from the contact surface to the surface of the magnetic armature 102 and the conductor 201 and further elongate, elongating the arc, cooling the arc temperature, accelerating the arc ionization, and accelerating the arc extinguishing. If the arc cannot be extinguished in this way, the arc will continue to be guided to the arc extinguishing grid 400. At this time, the magnetic armature 102 will assume the function of the arc striking angle, and the arc will be guided into the arc extinguishing chamber composed of the arc extinguishing grid 400 through the arc striking angle and extinguished.

[0056] pass Figure 6 , showing another connection scheme of the soft wire 800 different from the above-mentioned embodiment, the soft wire 800 is welded on the moving contact 103. This scheme makes the position of the soft wire more flexible and can be selected according to the actual situation of the electrical product using this contact system.

[0057] Figure 7 Another solution for connecting a soft wire 800 is shown. The soft wire 800 is welded on the moving contact assembly 100 near the rotating fulcrum. This solution can make the moving contact assembly 100 conductive, which is convenient for arranging the connection terminal near the rotating fulcrum 1001.

[0058] Figure 8 The figure shows the stress condition of a soft wire 800 welded on a moving contact 103. The structure allows the soft wire 800 to pass through its own semicircular arc shape. When a counterclockwise current flows through it, the direction of the internal magnetic field lines of force is vertically outward. The current of the soft wire 800 welded on the moving contact 103 generates a downward electromagnetic force to the right, which is superimposed on the moving contact 103, thereby increasing the stability of the moving contact 103.

[0059] Fig. 9 It is shown that when the moving contact assembly 100 is opened, the angle α between the magnetic armature 102 and the U-shaped magnetic yoke 202 is an acute angle.

[0060] Second embodiment:

[0061] like Figure 10 to Figure 11 As shown in FIG. 1 , another embodiment of the present invention is different from the first embodiment in that: on the basis of the first embodiment, the soft wire 800 is welded to the rotating fulcrum 1001 of the moving contact assembly 100 or the front or rear of the rotating fulcrum 1001. In addition, a mechanism for assisting in increasing the contact pressure is arranged near the driving fulcrum 1002 according to the current flow position in the moving contact assembly 100, and the mechanism for assisting in increasing the contact pressure includes a second armature 1004 and a second U-shaped yoke 2002, wherein the second U-shaped yoke 2002 is riveted near the driving fulcrum 1002 of the contact assembly 100, and the second U-shaped yoke 2002 arranged corresponding thereto is clamped on the insulating housing 700.

[0062] The induced magnetic field generated by the auxiliary mechanism for increasing the contact pressure magnetizes the second U-shaped yoke 2002 into magnetic poles, and a suction force is generated between the magnetic poles on the second armature 1004. The suction force can make the moving contact assembly 100 more stable, so that it compensates for the Holm force between the moving and static contacts, and increases the suction force to overcome the Holm force. Furthermore, a gap γ is provided between the second armature 1004 and the second U-shaped yoke 2002, and γ≥0.1mm. The auxiliary mechanism for increasing the contact pressure can also be used alone to compensate for the Holm force between the moving and static contacts. Due to such improvements, the short-circuit current tolerance of the contact system is improved, and the short-time tolerance is further improved.

[0063] The present invention can be realized in other specific forms without departing from its spirit and essential characteristics. The current embodiment is considered to be exemplary and not restrictive in all aspects, and the scope of the present invention is defined by the appended claims rather than the above description, and all changes falling within the meaning of the claims and the scope of equivalents are thus included in the scope of the present invention.

[0064] The present invention can be realized in other specific forms without departing from its spirit and essential characteristics. The current embodiment is considered to be exemplary and not restrictive in all aspects, and the scope of the present invention is defined by the appended claims rather than the above description, and all changes falling within the meaning of the claims and the scope of equivalents are thus included in the scope of the present invention.

Claims

1. A contact system for a switch, the contact system comprising at least: A moving contact assembly, a stationary contact assembly, and an insulating shell for arranging the moving contact assembly and the stationary contact assembly; one end of the moving contact assembly is a rotating fulcrum and the other end is provided with a moving contact, the moving contact assembly rotates around the rotating fulcrum to contact or separate from the stationary contact assembly, a driving fulcrum is provided in the middle of the moving contact assembly, a magnetic armature is provided in front of the moving contact, the stationary contact assembly at least includes a conductor and a stationary contact, a U-shaped yoke is provided on the conductor below corresponding to the magnetic armature; when the moving contact contacts the stationary contact, a gap of at least 0.2 mm is provided between the magnetic armature and the two end surfaces of the U-shaped yoke, and when the moving contact separates from the stationary contact, an acute angle is provided between the magnetic armature and the two end surfaces of the U-shaped yoke.

2. The contact system of the switch according to claim 1, characterized in that: A soft wire is arranged on the moving contact or the front or rear of the moving contact.

3. The contact system of the switch according to claim 1, characterized in that: A soft wire is arranged at the rotation fulcrum of the moving contact assembly or at the front or rear of the rotation fulcrum.

4. The contact system of the switch according to claim 1, characterized in that: A second U-shaped magnetic yoke is arranged in front of and / or behind the driving fulcrum.

5. The contact system of the switch according to claim 4, characterized in that: A second armature is provided on the insulating shell below the second U-shaped magnetic yoke in a corresponding gap shape.

6. The contact system of the switch according to claim 5, characterized in that: The second U-shaped magnetic yokes are arranged in at least one pair.

7. The contact system of the switch according to claim 2, characterized in that: The insulating housing is provided with at least one first wiring terminal and one second wiring terminal.

8. The contact system of the switch according to claim 7, characterized in that: The flexible wire is directly or indirectly connected to the first connecting terminal.

9. The contact system of the switch according to claim 7, characterized in that: The stationary contact assembly is connected to or integrated with the second wiring terminal.

10. The contact system of the switch according to claim 1, characterized in that: At least two arc-extinguishing grids are arranged in front of the magnetic armature and the U-shaped magnetic yoke.

11. The contact system of the switch according to claim 1, characterized in that: The contact system is driven by an electromagnetic system or a motor reduction system.

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