A moving contact assembly and contact arc extinguishing device

Abstract

The application relates to the technical field of low-voltage electrical apparatus, in particular to a moving contact assembly and a contact arc extinguishing device. The moving contact assembly comprises a rotating shaft, a moving contact piece connecting shaft, at least one moving main contact and at least one moving main arc contact; the moving contact piece connecting shaft is installed on the rotating shaft through the holes in the tail portions of the moving main contact and the moving main arc contact, one end of the moving main contact and one end of the moving main arc contact are connected to the rotating shaft through the moving contact piece connecting shaft, the moving main contact is provided with a moving main contact point on the moving contact piece, the moving main arc contact is provided with a moving main arc contact point on the moving contact piece, and the projection of the movement trajectories of the moving main contact point and the moving main arc contact point on the axial direction of the rotating shaft at least partially overlaps; the moving main contact and the moving main arc contact are both used for extending into the inner cavity of the arc extinguishing chamber. By making the distance from the end surface of the moving main contact and the moving main arc contact close to the arc extinguishing chamber to the rotating center of the moving contact piece connecting shaft equal, both can extend into the inner cavity of the arc extinguishing chamber, and the arc extinguishing effect is improved.

Description

Technical Field

[0001] This invention relates to the field of low-voltage electrical technology, and in particular to a moving contact assembly and a contact arc extinguishing device. Background Technology

[0002] In the low-voltage power distribution field, circuit breakers are critical protective devices. When a circuit breaker breaks a circuit, an electric arc is generated between its contacts. If this arc cannot be extinguished in time, it will seriously affect the service life of the circuit breaker and system safety. Existing circuit breakers typically employ a multi-contact structure, with the moving contacts consisting of short main contacts and long arc contacts. The main contacts carry current, while the arc contacts both carry and break current. Existing arc-extinguishing chambers include a front-opening outer shell and an arc-extinguishing grid assembly housed within the shell, with the moving contacts located at the front of the arc-extinguishing chamber. However, in this structure, the arc contacts extend into the arc-extinguishing chamber, while the main contacts are located outside. The electric arc generated on the main contacts has difficulty entering the arc-extinguishing chamber, especially when breaking large currents, where the arc on the main contacts cannot be effectively extinguished, affecting the breaking reliability of the circuit breaker. Summary of the Invention

[0003] The purpose of this invention is to provide a moving contact assembly and a contact arc extinguishing device to solve the technical problem in the prior art where the main contact is located outside the arc extinguishing chamber, making it difficult for the electric arc generated on the main contact to enter the arc extinguishing chamber, thus affecting the reliability of the disconnection.

[0004] In a first aspect, the present invention provides a moving contact assembly for a contact arc extinguishing device, the contact arc extinguishing device including an arc extinguishing chamber, the moving contact assembly being disposed on the front side of the arc extinguishing chamber, the arc extinguishing chamber including a housing with a front opening and an arc extinguishing grid assembly disposed within the housing, the moving contact assembly including: a rotating shaft, a moving contact connecting shaft, at least one moving main contact and at least one moving main arc contact; The movable contact connecting shaft passes through the holes at the tail of the movable main contact and the movable main arc contact and is mounted on the rotating shaft. One end of the movable main contact and one end of the movable main arc contact are both connected to the rotating shaft through the movable contact connecting shaft. Both the movable main contact and the movable main arc contact include at least one movable contact piece arranged along the axial direction of the rotating shaft. The movable contact piece of the movable main contact is provided with a movable main contact point, and the movable contact piece of the movable main arc contact is provided with a movable main arc contact point. The motion trajectories of the movable main contact point and the movable main arc contact point are projected onto the axial direction of the rotating shaft in at least partially overlapping directions. Both the moving main contact and the moving main arc contact are used to extend into the inner cavity of the arc-extinguishing chamber. The moving main arc contact contacts the stationary contact earlier than the moving main contact contacts the stationary contact, and the moving main arc contact separates from the stationary contact later than the moving main contact separates from the stationary contact.

[0005] In an optional embodiment, the arc-extinguishing chamber includes a first partition disposed within the outer shell, the first partition dividing the inner cavity of the arc-extinguishing chamber into at least one first arc channel and at least one second arc channel, and along the axial direction of the rotating shaft, the width of the first arc channel is smaller than the width of the second arc channel; The moving main arc contact is used to extend into the first arc channel, and the moving main contact is used to extend into the second arc channel.

[0006] In an optional embodiment, the moving main contact includes at least one main contact and at least one moving secondary arc contact, and both the main contact and the moving secondary arc contact include at least one moving contact piece; The time when the moving secondary arc contact contacts the stationary contact is earlier than the time when the main contact contacts the stationary contact but later than the time when the moving main arc contact contacts the stationary contact; the time when the moving secondary arc contact separates from the stationary contact is later than the time when the main contact separates from the stationary contact but earlier than the time when the moving main arc contact separates from the stationary contact.

[0007] In an optional embodiment, two main contacts are provided, and one moving secondary arc contact is provided, with the moving secondary arc contact located between the two main contacts along the axial direction of the rotating shaft. or; The main contact is provided, and the moving secondary arc contact is provided. Along the axial direction of the rotating shaft, the main contact is located between the moving main arc contact and the moving secondary arc contact.

[0008] In an optional embodiment, the arc-extinguishing chamber further includes a second partition disposed within the outer casing, the second partition dividing the second arc channel into at least one first arc sub-channel and at least one second arc sub-channel; The moving secondary arc contact is used to extend into the first arc sub-channel, and the main contact is used to extend into the second arc channel.

[0009] In an optional embodiment, the number of moving contact pieces included in the moving main contact is greater than the number of moving contact pieces included in the moving main arc contact; A guide vane is provided inside the second arc channel to make the second arc channel wider at the front and narrower at the back.

[0010] In an optional embodiment, the rotating shaft is provided with an abutment surface, and both the moving main contact and the moving main arc contact are abutted against the abutment surface by springs; The contact surface is provided with a first groove corresponding to the moving main arc contact, and the moving main arc contact is disposed in the first groove, so that the time when the moving main arc contact contacts the stationary contact is earlier than the time when the moving main contact contacts the stationary contact, and the time when the moving main arc contact separates from the stationary contact is later than the time when the moving main contact separates from the stationary contact.

[0011] In an optional embodiment, a second groove is provided on the abutting surface corresponding to the moving secondary arc contact, the moving secondary arc contact is disposed in the second groove, and the depth of the first groove is greater than the depth of the second groove, so that the moving secondary arc contact contacts the stationary contact earlier than the main contact contacts the stationary contact, and the moving secondary arc contact separates from the stationary contact later than the main contact separates from the stationary contact.

[0012] In an optional embodiment, the distances from the end faces of the moving main contact and the moving main arc contact near the arc-extinguishing chamber to the rotation center of the moving contact connecting shaft are equal; and / or the distances from the end faces of the moving main contact and the moving main arc contact near the arc-extinguishing chamber to the moving contact connecting shaft are equal. All the moving main arc contacts on all the moving contact pieces of the moving main arc contact are located inside the arc extinguishing chamber.

[0013] In a second aspect, the present invention provides a contact arc extinguishing device, comprising a contact system and an arc extinguishing chamber, wherein the contact system comprises a stationary contact and a moving contact assembly as described in any of the foregoing embodiments, and the arc extinguishing chamber comprises a housing with a front opening and an arc extinguishing grid assembly disposed within the housing; The arc-extinguishing chamber further includes a first partition disposed within the outer casing. The first partition divides the inner cavity of the arc-extinguishing chamber into at least one first arc channel and at least one second arc channel. The arc-extinguishing grid assembly includes a first grid assembly and a first upper arc-leading element located within the first arc channel, and a second grid assembly and a second upper arc-leading element located within the second arc channel. The shortest distance between the first upper arc-leading element and the second upper arc-leading element near the corresponding moving main arc contact and the end face of the moving main contact is less than 3mm in the height direction (vertical direction) and less than 3mm in the length direction (front-back direction).

[0014] Compared with the prior art, the technical advantages of the moving contact assembly and contact arc extinguishing device provided by the present invention are as follows: The moving contact assembly provided by the present invention includes a rotating shaft, a moving contact plate connecting shaft, at least one moving main contact, and at least one moving main arc contact. The moving contact plate connecting shaft is mounted on the rotating shaft through holes at the tails of the moving main contact and the moving main arc contact. One end of the moving main contact and one end of the moving main arc contact are both connected to the rotating shaft via the moving contact plate connecting shaft. Both the moving main contact and the moving main arc contact include at least one moving contact plate arranged along the axial direction of the rotating shaft. The moving contact plate of the moving main contact is provided with a moving main contact point, and the moving contact plate of the moving main arc contact is provided with a moving main arc contact point. The projections of the movement trajectories of the moving main contact and the moving main arc contact point onto the axial direction of the rotating shaft at least partially overlap. Both the moving main contact and the moving main arc contact are used to extend into the inner cavity of the arc-extinguishing chamber. The contact time between the moving main arc contact and the stationary contact is earlier than the contact time between the moving main contact and the stationary contact, and the separation time between the moving main arc contact and the stationary contact is later than the separation time between the moving main contact and the stationary contact.

[0015] By equipping the distances from the end faces of the moving main contact and the moving main arc contact near the arc-extinguishing chamber to the rotation center of the moving contact connecting shaft, both the moving main contact and the moving main arc contact can extend into the inner cavity of the arc-extinguishing chamber, reducing the length of the arc-extinguishing chamber in the direction of the moving contact's extension. Compared to the existing structure where the main contact is located outside the arc-extinguishing chamber, the moving main contact can also extend into the inner cavity of the arc-extinguishing chamber, allowing the arc generated on the moving main contact to enter the arc-extinguishing chamber and be extinguished. Especially during high-current breaking, the arc on the moving main contact will not be unable to be extinguished due to its location outside the arc-extinguishing chamber, thus improving the arc-extinguishing effect and breaking reliability of the circuit breaker. Furthermore, since the distances from the moving main contact and the moving main arc contact to the rotation center of the moving contact connecting shaft are equal, both can be manufactured using the same molds and processes, reducing manufacturing costs.

[0016] The contact arc extinguishing device provided by the present invention includes the above-mentioned moving contact assembly. Therefore, the technical advantages and effects achieved therefrom include the technical advantages and effects achieved by the above-mentioned moving contact assembly, which will not be described in detail here.

[0017] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the structure of the moving contact assembly provided in the embodiment of the present invention when a moving secondary arc contact is provided; Figure 2This is a schematic diagram of the structure of the moving contact assembly provided in an embodiment of the present invention when no moving secondary arc contact is provided; Figure 3 This is a schematic diagram of the contact arc extinguishing device provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the interior of the arc-extinguishing chamber provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the external exterior of the arc-extinguishing chamber provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the installation of the contact arc extinguishing device provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of an integral structure of the first grid group and the second grid group provided in an embodiment of the present invention; Figure 8 This is a schematic diagram showing that the first grid group and the second grid group are an integral structure with interconnected channels, as provided in an embodiment of the present invention; Figure 9 This is a schematic diagram showing that the first grid group and the second grid group are an integral structure with channels separated, as provided in an embodiment of the present invention; Figure 10 The schematic diagram of the contact arc extinguishing device provided in the embodiment of the present invention shows that the first grid plate group and the second grid plate group are separate structures. Figure 11 This is a schematic diagram showing that the first grid group and the second grid group provided in this embodiment of the invention have separate structures and are separated by channels; Figure 12 This is a schematic diagram of the rear side of the rear shell provided in an embodiment of the present invention; Figure 13 A schematic diagram of one side of the rear shell provided in an embodiment of the present invention, where the rear shell has two side plates; Figure 14 This is a schematic diagram of the other side when the rear shell has two side plates, as provided in an embodiment of the present invention. Figure 15 This is a schematic diagram of the connection shaft between the spring and the moving contact piece provided in an embodiment of the present invention.

[0020] Icons: 1-Moving contact assembly; 2-Contact arc extinguishing device; 3-Arc extinguishing chamber; 4-Housing shell; 5-Arc extinguishing grid assembly; 6-Rotating shaft; 7-Moving main contact; 8-Moving main arc contact; 9-First partition; 10-First arc channel; 11-Second arc channel; 12-Main contact; 13-Moving secondary arc contact; 14-Guide plate; 15-Abutting surface; 16-First groove; 17-Second groove; 18-Moving main contact; 19-Moving main arc contact; 20-First upper arc-drawing component; 21-Second upper arc-drawing component; 22-Rear shell; 23-Housing shell; 24-Stationary contact; 25-First grid assembly; 26-Second grid assembly; 27-Main contact; 28-Moving secondary arc contact; 29-Stationary contact; 30-Spring; 31-Moving contact connecting shaft; 32-Spring hanging plate. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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.

[0022] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0025] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0026] The specific structure is as follows: Figures 1 to 15 As shown.

[0027] This embodiment provides a moving contact assembly 1 for a contact arc extinguishing device 2. The contact arc extinguishing device 2 includes an arc extinguishing chamber 3. The moving contact assembly 1 is disposed on the front side of the arc extinguishing chamber 3. The arc extinguishing chamber 3 includes a housing 4 with a front opening and an arc extinguishing grid assembly 5 disposed within the housing 4. The moving contact assembly 1 includes: a rotating shaft 6, a moving contact connecting shaft 31, at least one moving main contact 7, and at least one moving main arc contact 8. The moving contact connecting shaft 31 is mounted on the rotating shaft 6 through holes at the tails of the moving main contact 7 and the moving main arc contact 8. One end of the moving main contact 7 and one end of the moving main arc contact 8 are both connected to the rotating shaft 6 via the moving contact connecting shaft 31. Both the moving main contact 7 and the moving main arc contact 8 include at least one moving contact piece arranged axially along the rotating shaft 6. The distance from the end face of the moving main contact 7 and the moving main arc contact 8 near the arc extinguishing chamber 3 to the rotation center of the moving contact connecting shaft 31 is equal. Both the moving main contact 7 and the moving main arc contact 8 are used to extend into the inner cavity of the arc-extinguishing chamber 3. The moving main arc contact 8 contacts the stationary contact 24 earlier than the moving main contact 7 contacts the stationary contact 24, and the moving main arc contact 8 separates from the stationary contact 24 later than the moving main contact 7 separates from the stationary contact 24. By making the distance from the end face of the moving main contact 7 and the moving main arc contact 8 near the arc-extinguishing chamber 3 to the rotation center of the moving contact connecting shaft 31 equal, both can extend into the inner cavity of the arc-extinguishing chamber 3 without increasing the length of the arc-extinguishing chamber 3. Compared with the existing structure where the main contact is located outside the arc-extinguishing chamber, the moving main contact 7 can also extend into the inner cavity of the arc-extinguishing chamber 3, allowing the arc generated on the moving main contact 7 to enter the arc-extinguishing chamber 3 and be extinguished more quickly, thereby improving the arc-extinguishing effect and breaking reliability of the circuit breaker. At the same time, since the distance from both to the rotation center of the moving contact connecting shaft 31 is equal, they can be manufactured using the same molds and processes, reducing manufacturing costs.

[0028] In the existing technology, the short main contact is located outside the arc-extinguishing chamber, while the long arc contact extends into the arc-extinguishing chamber. If the short main contact were also placed in the arc-extinguishing chamber, the length of the arc-extinguishing chamber would be greatly increased.

[0029] The moving main contact 18 and the moving main arc contact 19 are block-shaped with a certain length, so the movement trajectory of each moving contact is a trajectory band. The trajectories overlap at least partially, so that the distance from each moving contact to the rotation center of the moving contact connecting shaft 31 can be the same or different, but the difference in distance is not large, that is, the difference in distance does not exceed the length of the moving contact. Then the distance from the end face of each moving contact near the arc-extinguishing chamber to the rotation center of the moving contact connecting shaft 31 is also the same or not significantly different. For example, the difference in distance from the end face of each moving contact near the arc-extinguishing chamber to the rotation center of the moving contact connecting shaft 31 does not exceed the length of the moving contact. Furthermore, when the distance from the end face of each moving contact near the arc-extinguishing chamber 3 to the end face of the corresponding moving contact near the arc-extinguishing chamber is the same, then the difference in distance from each moving contact to the rotation center of the moving contact connecting shaft is the difference in distance from the end face of each moving contact near the arc-extinguishing chamber to the rotation center of the moving contact connecting shaft. This reduces the length of the arc-extinguishing chamber when both the moving main contact 7 and the moving main arc contact 8 are inside the arc-extinguishing chamber. In this embodiment, the stationary contact 24 is provided with a stationary contact 29 that cooperates with the moving main contact 18 and the moving main arc contact 19. The stationary contact is flat and can be integral or separate. The stationary contact that cooperates with the moving main contact 18 and the moving main arc contact 19 has the same height as the contact point with the moving main contact 18 and the moving main arc contact 19.

[0030] In the closed state, regardless of whether the moving contacts are at a certain height in the circuit breaker height direction, or at a certain front-to-back position in the circuit breaker length direction, or whether the parts of the moving contacts near the arc-extinguishing chamber are at a certain height in the circuit breaker height direction, or at a certain front-to-back position in the circuit breaker length direction, as long as the distance from the end face of the moving contact near the arc-extinguishing chamber to the rotation center of the moving contact connecting shaft is the same or not significantly different, the technical effect of having both the moving main contact 7 and the moving main arc contact 8 inside the arc-extinguishing chamber and reducing the length of the arc-extinguishing chamber can be achieved.

[0031] In this embodiment, the moving main contact 7 and the moving main arc contact 8 include moving contact pieces with the same thickness and identical structure. Both pieces may have an arc-initiating angle or none may have one, allowing all moving contact pieces to be manufactured using the same mold and process, thus reducing manufacturing costs. Alternatively, an arc-initiating angle can be provided only on the moving contact piece of the moving main arc contact 8, while the other moving contact pieces do not, achieving the same arc-initiating effect.

[0032] In this embodiment, the arc-extinguishing chamber 3 includes a first partition 9 disposed within the outer casing 4. The first partition 9 divides the inner cavity of the arc-extinguishing chamber 3 into at least one first arc channel 10 and at least one second arc channel 11. The moving main arc contact 8 is used to extend into the first arc channel 10, and the moving main contact 7 is used to extend into the second arc channel 11. By dividing the inner cavity of the arc-extinguishing chamber 3 into two independent arc channels through the first partition 9, and by having the moving main arc contact 8 and the moving main contact 7 extend into different arc channels respectively, it is beneficial for the independent extinguishing of their respective arcs and avoids mutual interference.

[0033] This embodiment is not limited to this. The first partition 9 can be set on the bottom wall of the outer shell 4, or it can be integrally formed by a part of the wall of the outer shell 4, as long as it can divide the inner cavity of the arc extinguishing chamber 3 into two independent arc channels.

[0034] In this embodiment, the moving main contact 7 includes at least one main contact 12 and at least one moving secondary arc contact 13, and both the main contact 12 and the moving secondary arc contact 13 include at least one moving contact piece. The moving secondary arc contact 13 contacts the stationary contact 24 earlier than the main contact 12 contacts the stationary contact 24 but later than the moving main arc contact 8 contacts the stationary contact 24. The moving secondary arc contact 13 separates from the stationary contact 24 later than the main contact 12 separates from the stationary contact 24 but earlier than the moving main arc contact 8 separates from the stationary contact 24. By providing the moving secondary arc contact 13, when interrupting a large current, the arc generated on the main contact 12 can be ignited first by the moving secondary arc contact 13, thereby improving the reliability of arc extinguishing. This embodiment is not limited to this. One or more moving arc contacts 13 can be provided; they can be provided on one side of the main contact 12 or on both sides of the main contact 12, as long as they can make contact with the main contact 12 first and separate from the main contact 12 later.

[0035] In this embodiment, there are two main contacts 12 and one moving secondary arc contact 13. Along the axial direction of the rotating shaft 6, the moving secondary arc contact 13 is located between the two main contacts 12. Each main contact 12 includes one moving contact piece, and the moving secondary arc contact 13 includes two moving contact pieces.

[0036] This embodiment is not limited to this, and can also be: one main contact 12 is provided, one moving secondary arc contact 13 is provided, and along the axial direction of the rotating shaft 6, the main contact 12 is located between the moving main arc contact 8 and the moving secondary arc contact 13, wherein the main contact 12 includes three moving contact pieces, and the moving secondary arc contact 13 includes one moving contact piece.

[0037] Both of the above arrangements can achieve the following: the moving secondary arc contact 13 contacts the main contact 12 first and separates from the main contact 12 later. The choice can be made according to the actual breaking requirements.

[0038] As another implementation, the number and arrangement of the main contact 12 and the moving secondary arc contact 13 can be adjusted according to the number of poles and the breaking requirements. For example, there can be two moving secondary arc contacts 13, which are located on both sides of the main contact 12, or the main contact 12 and the moving secondary arc contact 13 can be arranged alternately. They are not limited to the two mentioned above.

[0039] By setting the moving secondary arc contact 13, the contact time between the moving secondary arc contact 13 and the stationary contact 24 is earlier than the contact time between the main contact 12 and the stationary contact 24 and later than the contact time between the moving main arc contact 8 and the stationary contact 24. The separation time between the moving secondary arc contact 13 and the stationary contact 24 is later than the separation time between the main contact 12 and the stationary contact 24 and earlier than the separation time between the moving main arc contact 8 and the stationary contact 24.

[0040] When disconnecting a small current, such as the rated current, the operating mechanism drives the rotating shaft 6 to rotate, causing the moving contact assembly 1 to separate from the stationary contact 24. Since the moving main arc contact 8 and the stationary contact 24 are separated last, an arc is generated between the moving main arc contact 8 and the stationary contact 24. Because the arc of disconnecting a small current is relatively weak, if the moving main arc contact 8 is located outside the arc-extinguishing chamber, the arc will have difficulty entering the arc-extinguishing grid assembly 5. Therefore, the moving main arc contact 8 is extended into the first arc channel 10 to make it easier for the arc to enter the arc-extinguishing grid assembly 5. Furthermore, the width of the first arc channel 10 is set to a narrow slit that matches the width of the moving main arc contact 8, making it easier for the arc to enter the arc-extinguishing grid assembly 5. However, as the number of breaking cycles increases, the contacts of the moving main arc contact 8 gradually wear down, the overtravel gradually decreases, and the arc-initiating effect weakens. At this time, the moving secondary arc contact 13 is added to play the role of arc initiation, and the moving secondary arc contact 13 extends into the second arc channel 11, making it easier for the arc to enter the arc-extinguishing grid group 5, ensuring successful disconnection of small currents. By setting the moving secondary arc contact 13, the service life of the circuit breaker can be increased.

[0041] When a large current, such as a short-circuit current, is interrupted, under the enormous electrodynamic repulsion force, all the moving contacts of the moving contact assembly 1 repel each other almost simultaneously. An electric arc is generated between the moving main arc contact 8 and the stationary contact 24, and also between the moving main contact 7 and the stationary contact 24. The arc then enters the arc-extinguishing grid assembly 5 through the first arc channel 10 and the second arc channel 11. When the distance from the moving main contact to the rotation center of the rotating shaft 6 is the same, the final pressure of the moving secondary arc contact 13 is equal to the final pressure of the main contact 12. Therefore, the moving secondary arc contact 13 and the main contact 12 repel each other simultaneously. Since the moving main contact 7 extends into the second arc channel 11, the arc easily enters the arc-extinguishing grid assembly 5.

[0042] In this embodiment, the arc-extinguishing chamber 3 further includes a second partition disposed within the outer casing 4. The second partition divides the second arc channel 11 into at least one first arc sub-channel and at least one second arc sub-channel. The moving secondary arc contact 13 is used to extend into the first arc sub-channel, and the main contact 12 is used to extend into the second arc sub-channel. By further dividing the second arc channel 11 through the second partition, the moving secondary arc contact 13 and the main contact 12 extend into different sub-channels, which is beneficial for the independent extinguishing of their respective arcs, avoids mutual interference, and further improves the arc-extinguishing effect. Furthermore, the width of the first arc sub-channel is set to a narrow slit adapted to the width of the moving secondary arc contact 13, making it easier for the arc to enter the arc-extinguishing grid assembly 5.

[0043] This embodiment is not limited to this. The second partition can be set on the bottom wall of the outer shell 4, or it can be integrally formed by a part of the wall of the outer shell 4, as long as it can divide the second arc channel 11 into multiple sub-channels.

[0044] In this embodiment, the moving main contact 7 includes a greater number of moving contact pieces than the moving main arc contact 8. Along the axial direction of the rotating shaft 6, the width of the first arc channel 10 is smaller than the width of the second arc channel 11. A guide plate 14 is provided in the second arc channel 11 to form a channel that is wider at the front and narrower at the back. By having more moving contact pieces in the moving main contact 7 than in the moving main arc contact 8, the moving main contact 7 can carry a larger current. Because the moving main contact 7 has a larger number of moving contact pieces, the width of its corresponding second arc channel 11 is also correspondingly larger, while the moving main arc contact 8 has a smaller number of moving contact pieces, and the width of its corresponding first arc channel 10 is also correspondingly smaller. The guide plate 14 makes the second arc channel 11 form a channel that is wider at the front and narrower at the back, which is beneficial for the arc generated on the moving main contact 7 to quickly enter the arc extinguishing grid plate group 5.

[0045] This embodiment is not limited to this. The guide plate 14 can be an independent plate-shaped component, or a guide protrusion formed on the inner wall of the outer shell 4, or a guide slope set on the first partition 9 or the second partition, as long as it can make the second arc channel 11 form a channel that is wider at the front and narrower at the back.

[0046] Furthermore, a guide plate 14 is provided in the second arc sub-channel to form a channel that is wider at the front and narrower at the back, which is conducive to the rapid entry of the arc generated on the main contact 12 into the arc extinguishing grid plate group 5.

[0047] In this embodiment, a contact surface 15 is provided on the rotating shaft 6 near the arc-extinguishing chamber. The surfaces of the moving main contact 7 and the moving main arc contact 8 facing the stationary contact 24 are both abutted against the contact surface 15 by springs 30. One end of the spring 30 is connected to the surface of the moving contact plate facing the stationary contact 24, and the other end is connected to a spring mounting plate 32, which is mounted on the rotating shaft 6. A first groove 16 is provided on the contact surface 15 corresponding to the moving main arc contact 8. The moving main arc contact 8 is disposed in the first groove 16 so that the contact time between the moving main arc contact 8 and the stationary contact 24 is earlier than the contact time between the moving main contact 7 and the stationary contact 24, and the separation time between the moving main arc contact 8 and the stationary contact 24 is later than the separation time between the moving main contact 7 and the stationary contact 24. The first groove 16 makes the moving main arc contact 8 closer to the stationary contact 24 relative to the moving main contact 7, thereby achieving a timing sequence of contact before separation.

[0048] This embodiment is not limited to this. The same timing can also be achieved by providing a protrusion on the surface of the moving main contact 7 facing the contact surface 15 or by providing a contact pad on the moving contact piece of the moving main contact 7.

[0049] There are many other structural solutions to achieve the timing sequence of contact before separation. For example, a contact surface is provided on the rotating shaft 6 away from the arc-extinguishing chamber. The surfaces of the moving main contact 7 and the moving main arc contact 8 that are away from the stationary contact are both abutted against the contact surface by the spring 30. A groove is provided on the contact surface corresponding to the moving main arc contact 8.

[0050] For example, an abutting shaft is provided on the rotating shaft 6 away from the arc-extinguishing chamber. The surfaces of the moving main contact 7 and the moving main arc contact 8 that are away from the stationary contact are abutted against the abutting shaft by the spring 30. A groove is provided on the abutting shaft corresponding to the moving main arc contact 8.

[0051] In this embodiment, a second groove 17 is provided on the contact surface 15 corresponding to the moving secondary arc contact 13. The moving secondary arc contact 13 is disposed in the second groove 17, and the depth of the first groove 16 is greater than the depth of the second groove 17. This is to ensure that the moving secondary arc contact 13 contacts the stationary contact 24 earlier than the main contact 12 contacts the stationary contact 24, and that the moving secondary arc contact 13 separates from the stationary contact 24 later than the main contact 12 separates from the stationary contact 24. The second groove 17 brings the moving secondary arc contact 13 closer to the stationary contact 24 relative to the main contact 12, thereby achieving a timing sequence of contact followed by separation.

[0052] This embodiment is not limited to this; the same timing can also be achieved by providing a protrusion on the moving secondary arc contact 13 or by providing an abutment pad on the moving contact piece of the moving secondary arc contact 13.

[0053] In this embodiment, the moving main contact 7 has a moving main contact 18 on its moving contact piece, and the moving main arc contact 8 has a moving main arc contact 19 on its moving contact piece. The distances from the moving main contact 18 and the moving main arc contact 19 to the rotation center of the rotating shaft 6 are equal or unequal. All moving main contacts 18 on all moving contact pieces of the moving main contact 7 are located within the inner cavity of the arc-extinguishing chamber 3. All moving main arc contacts 19 on all moving contact pieces of the moving main arc contact 8 are located within the inner cavity of the arc-extinguishing chamber 3. Specifically, if the moving main contact 7 includes a main contact 12 and a moving secondary arc contact 13, the moving main contact 18 includes a main contact 27 disposed on the main contact 12 and a moving secondary arc contact 28 disposed on the moving secondary arc contact 13. The main contact 27 is used to make contact with the stationary contact 24 to conduct electricity. The moving main arc contact 19 is disposed on the moving contact piece of the moving main arc contact 8 and is used to initiate arcing when interrupting small currents. The moving secondary arc contact 28 serves as a spare for the moving main arc contact 8 and is used to initiate arcing when interrupting small currents. The distances from the main contact 27, the moving secondary arc contact 28, and the moving main arc contact 19 to the rotation center of the rotating shaft 6 may be equal or unequal, and can be selected according to actual needs. If the moving main contact 7 only includes the main contact 12, then the moving main contact 18 includes the main contact 27 disposed on the main contact 12. The main contact 27 is used to make contact with the stationary contact 24 to conduct electricity.

[0054] By setting the above contact points, reliable contact between each contact and the stationary contact 24 and the accuracy of the breaking sequence are ensured.

[0055] This embodiment is not limited to this. The main contact 27, the moving secondary arc contact 28 and the moving main arc contact 19 can be made of the same material or different materials, such as silver-tungsten alloy, copper-tungsten alloy or silver tin oxide, etc.

[0056] In this embodiment, the working process of the moving contact assembly 1 is as follows: During closing, the moving main arc contact 8 first contacts the stationary contact 24, then the moving secondary arc contact 13 contacts the stationary contact 24, and finally the main contact 12 contacts the stationary contact 24. During opening, the main contact 12 first separates from the stationary contact 24, then the moving secondary arc contact 13 separates from the stationary contact 24, and finally the moving main arc contact 8 separates from the stationary contact 24. When interrupting small currents, the arc is mainly generated on the moving main arc contact 8 and is extinguished in the first arc channel 10. When the arc-initiating effect of the moving main arc contact 8 weakens, the moving secondary arc contact 13 takes over the arc-initiating function, and the arc is extinguished in the first arc sub-channel. When interrupting large currents, arcs are also generated on the main contact 12 and the moving secondary arc contact 13. At this time, the arcs are extinguished in the first and second arc sub-channels respectively, thus ensuring the reliability of the interruption.

[0057] When interrupting a small current, the arc may not easily enter the arc-extinguishing chamber and may retreat towards the shaft, causing the moving main arc contact 8 and the stationary contact 24 to break down at the shortest distance. Therefore, an insulating element can be installed on the belly of the moving main arc contact 8, that is, the part between the moving main contact 18 and the shaft facing the stationary contact, to ensure successful interruption of small currents.

[0058] When breaking high-voltage (e.g., 800V, 1500V) and high-current circuits, although the arc under high current is more likely to enter the arc-extinguishing chamber, some charged particles will still diffuse between the moving main contact 7 and the stationary contact 24. Under high voltage, this can cause the moving main contact 7 and the stationary contact 24 to break down at their shortest distance. Therefore, an insulating component can be installed on the belly of the moving main contact 7, i.e., the part between the moving main contact 18 and the rotating shaft facing the stationary contact, to ensure successful breaking of high-voltage and high-current circuits.

[0059] When interrupting a large current at a low voltage (e.g., 400V), although the arc under the large current is more likely to enter the arc-extinguishing chamber, some charged particles will still diffuse between the moving main contact 7 and the stationary contact 24. However, under low voltage, this usually will not cause the moving main contact 7 and the stationary contact 24 to break down at the shortest distance. Therefore, an insulating part is not required on the belly of the moving main contact 7, that is, the part between the moving main contact 18 and the shaft facing the stationary contact.

[0060] Of course, the preferred solution is to provide insulating elements on both the moving main arc contact 8 and the moving main contact 7.

[0061] This embodiment provides a contact arc extinguishing device 2, including a contact system and an arc extinguishing chamber 3. The contact system includes a stationary contact 24 and the aforementioned moving contact assembly 1. The arc extinguishing chamber 3 includes a front-opening outer shell 4 and an arc extinguishing grid assembly 5 disposed within the outer shell 4. The arc extinguishing chamber 3 also includes a first partition 9 disposed within the outer shell 4, which divides the inner cavity of the arc extinguishing chamber 3 into at least one first arc channel 10 and at least one second arc channel 11. The arc extinguishing grid assembly 5 includes a first grid assembly 25 and a first upper arc-drawing member 20 located within the first arc channel 10, and a second grid assembly 26 and a second upper arc-drawing member 21 located within the second arc channel 11. The projections of the first upper arc-drawing member 20 and the second upper arc-drawing member 21 in the axial direction of the rotating shaft 6 overlap. Specifically, the projections of the first upper arc-drawing member 20 and the second upper arc-drawing member 21 in the width direction of the circuit breaker completely overlap. Since the distances from the end faces of the moving main contact 7 and the moving main arc contact 8 near the arc-extinguishing chamber to the rotation center of the rotating shaft 6 are equal, the first upper arc-drawing member 20 and the second upper arc-drawing member 21 corresponding to the moving main arc contact 8 and the moving main contact 7 can adopt the same shape. The ends of the two arc-drawing members near the moving contact assembly 1 do not need to be one in front of the other or one high and one low, thus reducing manufacturing costs. As another embodiment, the width of the second upper arc-drawing member 21 corresponding to the moving main contact 7 can be wider than the width of the first upper arc-drawing member 20 corresponding to the moving main arc contact 8, to accommodate situations where the number of moving contact pieces in the moving main contact 7 is greater than that in the moving main arc contact 8. In this embodiment, not only are the distances from the end faces of the moving main contact 7 and the moving main arc contact 8 near the arc-extinguishing chamber to the rotation center of the moving contact connecting shaft 31 equal, but also the distances from the end faces of the moving main contact 18 and the moving main arc contact 19 near the arc-extinguishing chamber 3 to the rotation center of the moving contact connecting shaft 31 are equal. Furthermore, the shapes of the moving main contact 7 and the moving main arc contact 8, which include the moving contact, from the rotation center of the moving contact connecting shaft 31 to the end face near the arc-extinguishing chamber 3 are consistent. And even further, the shapes of the moving main contact 7 and the moving main arc contact 8, which include the moving contact, are consistent.

[0062] Of course, when the first upper arc-drawing member 20 and the second upper arc-drawing member 21 draw arcs, the most vulnerable point is the shortest distance between the end faces of the corresponding moving main arc contacts 8 and 7. That is, in this embodiment, the shortest distance between the two arc-drawing members and the end faces of the moving contact assembly 1 does not need to be one in front of the other or one at the same height. When the positions of the shortest distances between the two arc-drawing members and the end faces of the moving contact assembly 1 are slightly different, the technical effect of this embodiment can still be achieved. Therefore, the shortest distance between the first upper arc-drawing member 20 and the second upper arc-drawing member 21 and the end faces of the corresponding moving main arc contacts 8 and 7 is less than 3mm in the height direction of the circuit breaker (i.e., the vertical direction) and less than 3mm in the length direction of the circuit breaker (i.e., the front-back direction). Preferably, the shortest distances are at the same position. Furthermore, the projections of the first upper arc-drawing member 20 and the second upper arc-drawing member 21 on the axial direction of the rotating shaft 6 overlap.

[0063] The outer casing 4 includes a front casing and a rear casing 22 that are spliced ​​together. The first partition 9 is disposed inside the front casing, and the front casing includes multiple casings 23 that are spliced ​​together along the axial direction of the rotating shaft 6. With the above structure, the contact arc extinguishing device 2 can simultaneously meet the breaking requirements of large current and critical small current, with good arc extinguishing effect and high reliability.

[0064] like Figures 7 to 9 As shown, when the first grid plate group 25 and the second grid plate group 26 are a single integrated grid plate group, the first partition plate 9 has a comb-shaped rod on the side near the grid plate and a plate on the side away from the grid plate. One side of the grid plate leg has an insertion groove that mates with the first partition plate 9, restricting the left and right movement of the first partition plate 9. The rod is inserted into the gap between adjacent grid plates and extends to the rear end of the grid plate, completely separating the gap between adjacent grid plates. Alternatively, the rod is inserted into the gap between adjacent grid plates but does not extend to the rear end of the grid plate, so the gap between adjacent grid plates is connected near the rear end of the grid plate, which is beneficial for heat dissipation. The first partition plate 9 is integrally formed with one of the shells 23 of the front shell. Of course, the plate can abut against the grid plate group or have a gap with the grid plate group. When there is a gap, the narrow slit of the first arc channel 10 remains, which is beneficial for heat dissipation and the transfer of the arc to the arc-extinguishing grid plate group 5, especially under high current conditions, where the effect is even better.

[0065] like Figure 10 and Figure 11 As shown, the first grid plate group 25 and the second grid plate group 26 can also be completely separated. For this purpose, the first grid plate group 25 and the second grid plate group 26 are separately arranged. The first partition plate 9 has grooves on both sides. The opposite side of the first grid plate group 25 and the second grid plate group 26 is inserted into the groove for positioning, and the opposite side is inserted into the grooves on the two inner sides of the rear shell 22 and / or the shell 23 for positioning. The first partition plate 9 extends to the rear end of the grid plate group 5, completely separating the first grid plate group 25 and the second grid plate group 26. The first partition plate 9 is integrally formed with one of the shells 23 of the front shell.

[0066] like Figure 12 When the first grid plate group 25 and the second grid plate group 26 are a single integral grid plate group, a comb-shaped rib can also be provided on the rear shell 22. The first partition plate 9 has a comb-shaped rod on the side near the grid plate. The rod is inserted into the gap between adjacent grid plates but does not extend to the rear end of the grid plate. The first partition plate 9 is integrally formed with one of the shells 23 of the front shell, and the comb-shaped rib is integrally formed with the rear shell 22. The comb-shaped rib is provided on the rear shell 22 to mate with the comb-shaped rod of the first partition plate 9, completely separating the gaps between adjacent grid plates.

[0067] like Figure 13 and Figure 14When the first grid plate group 25 and the second grid plate group 26 are a single integrated grid plate group, the rear shell 22 can be replaced with two side plates on both sides of the grid plate group, and the grid plates of the grid plate group are riveted to the side plates. The first partition plate 9 has a comb-shaped rod near the grid plate, which is inserted into the gap between adjacent grid plates but does not extend to the rear end of the grid plate. The first partition plate 9 is integrally formed with one of the shells 23 of the front shell. The comb-shaped rib is inserted and fixed to the grid plate group and abuts with the comb-shaped rod of the first partition plate 9, completely separating the gap between adjacent grid plates.

[0068] This embodiment is not limited to this. The first grid plate group 25 and the second grid plate group 26 can be separate structures and fixedly connected by means of buckles, rivets or screws, or they can be integral structures, as long as they can correspond to the first arc channel 10 and the second arc channel 11 respectively.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A moving contact assembly for a contact arc extinguishing device (2), the contact arc extinguishing device (2) comprising an arc extinguishing chamber (3), the moving contact assembly (1) disposed on the front side of the arc extinguishing chamber (3), the arc extinguishing chamber (3) comprising a housing (4) with a front opening and an arc extinguishing grid assembly (5) disposed within the housing (4), characterized in that, The moving contact assembly (1) includes: a rotating shaft (6), a moving contact plate connecting shaft (31), at least one moving main contact (7) and at least one moving main arc contact (8). The movable contact connecting shaft (31) passes through the holes at the tail of the movable main contact (7) and the movable main arc contact (8) and is mounted on the rotating shaft (6). One end of the movable main contact (7) and one end of the movable main arc contact (8) are both connected to the rotating shaft (6) through the movable contact connecting shaft (31). The movable main contact (7) and the movable main arc contact (8) each include at least one movable contact piece arranged along the axial direction of the rotating shaft (6). The movable contact piece of the movable main contact (7) is provided with a movable main contact point (18), and the movable contact piece of the movable main arc contact (8) is provided with a movable main arc contact point (19). The motion trajectories of the movable main contact point (18) and the movable main arc contact point (19) are projected onto the axial direction of the rotating shaft (6) in at least partially overlapping. Both the moving main contact (7) and the moving main arc contact (8) are used to extend into the inner cavity of the arc-extinguishing chamber (3), and the moving main arc contact (8) contacts the stationary contact (24) earlier than the moving main contact (7) contacts the stationary contact (24), and the moving main arc contact (8) separates from the stationary contact (24) later than the moving main contact (7) separates from the stationary contact (24).

2. The moving contact assembly according to claim 1, characterized in that, The arc-extinguishing chamber (3) includes a first partition (9) disposed inside the outer shell (4), the first partition (9) dividing the inner cavity of the arc-extinguishing chamber (3) into at least one first arc channel (10) and at least one second arc channel (11). The moving main arc contact (8) is used to extend into the first arc channel (10), and the moving main contact (7) is used to extend into the second arc channel (11).

3. The moving contact assembly according to claim 2, characterized in that, The moving main contact (7) includes at least one main contact (12) and at least one moving secondary arc contact (13), and both the main contact (12) and the moving secondary arc contact (13) include at least one moving contact piece; The time when the moving secondary arc contact (13) contacts the stationary contact (24) is earlier than the time when the main contact (12) contacts the stationary contact (24) and later than the time when the moving main arc contact (8) contacts the stationary contact (24). The time when the moving secondary arc contact (13) separates from the stationary contact (24) is later than the time when the main contact (12) separates from the stationary contact (24) and earlier than the time when the moving main arc contact (8) separates from the stationary contact (24).

4. The moving contact assembly according to claim 3, characterized in that, There are two main contacts (12) and one moving secondary arc contact (13). Along the axial direction of the rotating shaft (6), the moving secondary arc contact (13) is located between the two main contacts (12). or; One main contact (12) is provided, and one moving secondary arc contact (13) is provided. Along the axial direction of the rotating shaft (6), the main contact (12) is located between the moving main arc contact (8) and the moving secondary arc contact (13).

5. The moving contact assembly according to claim 3, characterized in that, The arc-extinguishing chamber (3) further includes a second partition disposed inside the outer shell (4), the second partition dividing the second arc channel (11) into at least one first arc sub-channel and at least one second arc sub-channel; The moving secondary arc contact (13) is used to extend into the first arc sub-channel, and the main contact (12) is used to extend into the second arc sub-channel.

6. The moving contact assembly according to claim 2, characterized in that, The number of moving contact pieces included in the moving main contact (7) is greater than the number of moving contact pieces included in the moving main arc contact (8); Along the axial direction of the rotating shaft (6), the width of the first arc channel (10) is smaller than the width of the second arc channel (11); A guide plate (14) is provided inside the second arc channel (11) so that the second arc channel (11) forms a channel that is wider at the front and narrower at the back.

7. The moving contact assembly according to claim 3, characterized in that, The rotating shaft (6) is provided with an abutment surface (15), and the moving main contact (7) and the moving main arc contact (8) are both abutted against the abutment surface (15) by springs (30). The contact surface (15) is provided with a first groove (16) corresponding to the moving main arc contact (8). The moving main arc contact (8) is disposed in the first groove (16) so that the moving main arc contact (8) contacts the stationary contact (24) earlier than the moving main contact (7) contacts the stationary contact (24), and the moving main arc contact (8) separates from the stationary contact (24) later than the moving main contact (7) separates from the stationary contact (24).

8. The moving contact assembly according to claim 7, characterized in that, The contact surface (15) is provided with a second groove (17) corresponding to the moving secondary arc contact (13). The moving secondary arc contact (13) is disposed in the second groove (17), and the depth of the first groove (16) is greater than the depth of the second groove (17), so that the moving secondary arc contact (13) contacts the stationary contact (24) earlier than the main contact (12) contacts the stationary contact (24), and the moving secondary arc contact (13) separates from the stationary contact (24) later than the main contact (12) separates from the stationary contact (24).

9. The moving contact assembly according to any one of claims 1-8, characterized in that, The distances from the end faces of the moving main contact (7) and the moving main arc contact (8) near the arc-extinguishing chamber (3) to the rotation center of the moving contact connecting shaft (31) are equal; and / or the distances from the end faces of the moving main contact (18) and the moving main arc contact (19) near the arc-extinguishing chamber (3) to the moving contact connecting shaft (31) are equal; All the moving main contacts (18) on all the moving contact pieces of the moving main contact (7) are located inside the cavity of the arc-extinguishing chamber (3); All the moving main arc contacts (19) on the moving contact pieces of the moving main arc contact (8) are located inside the arc extinguishing chamber (3).

10. A contact arc-extinguishing device, characterized in that, It includes a contact system and an arc-extinguishing chamber (3), the contact system including a stationary contact (24) and a moving contact assembly (1) according to any one of claims 1-9, the arc-extinguishing chamber (3) including a housing (4) with a front opening and an arc-extinguishing grid assembly (5) disposed in the housing (4). The arc-extinguishing chamber (3) further includes a first partition (9) disposed within the outer shell (4). The first partition (9) divides the inner cavity of the arc-extinguishing chamber (3) into at least one first arc channel (10) and at least one second arc channel (11). The arc-extinguishing grid assembly (5) includes a first grid assembly (25) and a first upper arc-leading element (20) located within the first arc channel (10), and a second grid assembly (26) and a second upper arc-leading element (21) located within the second arc channel (11). The first upper arc-leading element (20) and the second upper arc-leading element (21) are located at the shortest distance between the end faces of the corresponding moving main arc contact (8) and the moving main contact (7), with the distance in the circuit breaker height direction (i.e., the vertical direction) being less than 3 mm and the distance in the circuit breaker length direction (i.e., the front-to-back direction) being less than 3 mm.

Images