A molded case circuit breaker

Abstract

A plastic case circuit breaker. It is characterized in that: a linkage part is formed on the rotating shaft, the rear end of the lower contact assembly extends backward to below the rotating shaft, and a linkage cooperation part corresponding to the linkage part is formed. When closing, the rotating shaft can push the lower contact assembly to rotate upward to fit with the upper contact assembly. When opening, the lower contact assembly is separated from the rotating shaft and can automatically rotate downward. Its advantages are that when closing, the rotating shaft can contact the lower contact assembly to drive the lower contact assembly to act, realizing the closing action of the lower contact assembly and the upper contact assembly. When opening, the rotating shaft can be separated from the lower contact assembly, and the lower contact assembly can automatically open downward. Especially after the electric repulsive force generated by the superimposed short-circuit current, the opening speed of the upper contact assembly and the lower contact assembly is faster, which not only effectively increases the maximum opening distance, but also plays a role in quickly stretching the arc and effectively extinguishing the arc, and can greatly improve the rated working voltage of the circuit breaker. At the same time, the structure is simple and the assembly is convenient.

Description

Technical Field

[0001] The present invention relates to the field of low-voltage electrical appliances, and particularly to a molded case circuit breaker. Background Art

[0002] In order to improve the breaking speed of the moving and static contacts, increase the opening distance, and improve the arc extinguishing efficiency, some circuit breakers are provided with a structure in which the static contact is repellable.

[0003] Generally, the contact structure is specifically that the static contact is hinged on a bracket, the bracket is fixed on the base, and a torsion spring capable of lifting the static contact is provided on the bracket. During opening, since the static contact can be repelled and moved downward under the action of the electric repulsive force, the opening distance is increased and the breaking speed is improved. When the opening is completed, the static contact can move upward and reset under the action of the torsion spring to ensure reliable connection and contact between the moving and static contacts during closing. However, when the contact structure breaks, when the static contact moves downward under the action of the electric repulsive force, it will also be hindered by the restoring elastic force of the torsion spring, resulting in an unsatisfactory repelling effect of the static contact. At the same time, it is also difficult to increase the maximum opening distance of the contact, and the effect of extinguishing the arc of the contact cannot be effectively improved.

[0004] Another example is a large-opening-distance contact structure with fast breaking disclosed in Chinese invention patent (CN103617927B). It realizes the interlocking of the moving and static contacts through a connecting rod, so that the static contact rotates in the opposite rotation direction to the moving contact to form mutual fitting or separation, thereby increasing the maximum opening distance between the moving and static contacts. However, the breaking speed of this contact structure is limited by the action time of the operating mechanism, so the improvement of the breaking capacity is also limited, and the overall structure is more complex. When assembling, multiple parts need to be integrated and installed together, and the assembly is very difficult, and the process feasibility is relatively low. Summary of the Invention

[0005] In order to overcome the deficiencies of the background art, the present invention provides a molded case circuit breaker.

[0006] The technical solution adopted by the present invention: A molded case circuit breaker includes a base, a face cover, and a first terminal, an arc extinguishing chamber, a lower contact assembly, an upper contact assembly, a rotating shaft, an operating mechanism, a tripping mechanism, and a second terminal disposed in the base; the lower contact assembly is rotatably mounted on a bracket fixed to the base through a hinge shaft, the upper contact assembly is mounted on the rotating shaft, and the rotating shaft can drive the upper contact assembly to act, and connect or separate from the lower contact assembly; a linkage portion is formed on the rotating shaft, the rear end of the lower contact assembly extends backward to below the rotating shaft, and a linkage cooperation portion corresponding to the linkage portion is formed. During closing, the rotating shaft can push the lower contact assembly to rotate upward to fit with the upper contact assembly. During opening, the lower contact assembly is separated from the rotating shaft and can automatically rotate downward.

[0007] The linkage part on the rotating shaft is an arc-shaped structure.

[0008] An elastic member capable of driving the lower contact assembly to rotate downward is further provided between the lower contact assembly and the bracket.

[0009] The elastic member is of a double torsion spring structure, which includes two spring bodies and a U-shaped connecting rod connecting the two spring bodies. Elastic rods extend from both spring bodies. The two spring bodies of the elastic member are sleeved outside the hinge shaft and are respectively arranged on both sides of the lower contact assembly. The U-shaped connecting rod abuts against the lower contact assembly, and the elastic rod abuts against the bracket.

[0010] The lower contact assembly includes a lower contact and a lower contact support. The lower contact support is sleeved outside the lower contact. On both sides of the lower contact support, isolation covers with a "C"-shaped lower end opening are integrally formed. The elastic member is arranged inside the isolation cover.

[0011] The face cover is fixedly installed on the base, and an exhaust port corresponding to the arc extinguishing chamber is provided on the face cover. An arc isolation cover for separating the arc extinguishing chamber from the first terminal is provided inside the base. The arc isolation cover includes a partition plate and an exhaust channel extending in the direction of the first terminal. The exhaust channel extends to the other side of the first terminal.

[0012] The exhaust channel includes an inlet channel and an outlet channel. The inlet channel is of a reduced diameter structure, and its inlet size is larger than the outlet size.

[0013] At least one protruding blocking boss is formed on the side wall of the exhaust channel.

[0014] Two groups of exhaust channels are provided and are respectively arranged at both side positions of the partition plate. A plurality of guiding grooves are formed on the back surface of the partition plate, and the guiding grooves extend from the middle of the partition plate towards the exhaust channels on both sides.

[0015] An arc ignition member is provided below the arc extinguishing chamber. One end of the arc ignition member is connected to the first terminal, and the other end extends below the lower contact assembly and bends towards the arc extinguishing chamber.

[0016] The beneficial effects of the present invention are as follows: With the above scheme, when closing, the rotating shaft can contact the lower contact assembly to drive the lower contact assembly to act, realizing the closing action of the lower contact assembly and the upper contact assembly. When opening, the rotating shaft can be separated from the lower contact assembly, and the lower contact assembly can automatically open downward. Especially after the electric repulsive force generated by the superimposed short-circuit current, the opening speed of the upper contact assembly and the lower contact assembly is faster. It not only effectively increases the maximum opening distance, but also plays a role in quickly stretching the arc and effectively extinguishing the arc, and can greatly improve the rated working voltage of the circuit breaker. At the same time, the structure is simple and the assembly is convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1This is a schematic structural diagram of the molded case circuit breaker according to an embodiment of the present invention.

[0018] Figure 2 This is a cross-sectional view of the molded case circuit breaker when it is closed according to an embodiment of the present invention.

[0019] Figure 3 This is a cross-sectional view of the molded case circuit breaker when it is tripped according to an embodiment of the present invention.

[0020] Figure 4 This is a schematic structural diagram of the rotating shaft according to an embodiment of the present invention.

[0021] Figure 5 This is a schematic structural diagram of the lower contact assembly, bracket, and elastic member according to an embodiment of the present invention.

[0022] Figure 6 This is a schematic structural diagram of the lower contact assembly according to an embodiment of the present invention.

[0023] Figure 7 This is a schematic structural diagram of the elastic member according to an embodiment of the present invention.

[0024] Figure 8 This is a schematic structural diagram of the lower contact assembly, arc extinguishing chamber, first terminal, and arc guiding member according to an embodiment of the present invention.

[0025] Figure 9 This is a schematic structural diagram of the arc guiding member according to an embodiment of the present invention.

[0026] Figure 10 This is a cross-sectional view of the molded case circuit breaker according to an embodiment of the present invention.

[0027] Figure 11 It is Figure 10 an enlarged schematic view of part A in

[0028] Figure 12 This is a schematic structural diagram of the arc separating cover according to an embodiment of the present invention. Detailed Embodiments

[0029] The following further describes the embodiments of the present invention with reference to the accompanying drawings:

[0030] As Figures 1-7 shown, a molded case circuit breaker includes a base 1, a face cover 2, and a first terminal 3, an arc extinguishing chamber 4, a lower contact assembly 5, an upper contact assembly 6, a rotating shaft 7, an operating mechanism 8, a tripping mechanism 9, and a second terminal 10 disposed in the base 1.

[0031] The lower contact assembly 5 includes a lower contact 51 and a lower contact support 52. The lower contact support 52 is sleeved outside the lower contact 51 and is integrally connected to the lower contact 51. Moreover, the lower contact support 52 can substantially cover the upper side and the two side walls of the lower contact 51. The front end of the lower contact 51 is exposed outside the lower contact support 52 and forms a lower contact point. The lower end of the lower contact 51 forms a wiring boss, which can be connected to the first wiring terminal 3 through a flexible connection wire.

[0032] A bracket 12 is fixedly installed in the base 1. Installation hinge holes are correspondingly formed at positions near the middle of the lower contact 51 and the lower contact support 52, so that the lower contact assembly 5 can be rotatably installed on the bracket 12 through a hinge shaft 11.

[0033] The rotating shaft 7 is rotatably installed in the base 1 and is linked with the operating mechanism 8. It can rotate under the drive of the operating mechanism 8. The upper contact assembly 6 is installed on the rotating shaft 7. The upper contact point of the upper contact assembly 6 corresponding to the lower contact point of the lower contact assembly 5 is at the front end, and the other end is connected to the second wiring terminal 10 through a flexible connection wire. The upper contact assembly 6 can rotate with the rotating shaft 7. When the upper contact point contacts the lower contact point, it is connected, and when the upper contact point is separated from the lower contact point, it is disconnected.

[0034] A linkage part 71 is formed on the rotating shaft 7. The rear end of the lower contact support 52 extends backward to below the rotating shaft 7 and forms a linkage cooperation part 501 corresponding to the linkage part 71. The rotating shaft 7 can push the lower contact assembly 5 to rotate upward during closing to fit with the upper contact assembly 6.

[0035] Wherein, the linkage part 71 is an arc-shaped convex structure. When the linkage part 71 is in contact and cooperation with the linkage cooperation part 501, it can reduce friction and the action is more stable and reliable.

[0036] During closing, the rotating shaft 7 can drive the upper contact assembly 6 to rotate downward. At the same time, its linkage part 71 contacts the linkage cooperation part 501 of the lower contact assembly 5, pushing the lower contact assembly 5 to rotate upward, so that the upper contact assembly 6 and the lower contact assembly 5 are in contact to achieve closing;

[0037] During opening, under the combined action of the restoring elastic force of the operating mechanism and the electric repulsive force, the rotating shaft 7 drives the upper contact assembly 6 to rotate upward. At the same time, the linkage cooperation part 501 of the lower contact assembly 5 will lose the contact restriction of the linkage part 71 of the rotating shaft 7 on it, so that the lower contact assembly 5 can rotate downward under the action of the electric repulsive force, so that the upper contact assembly 6 and the lower contact assembly 5 are separated to achieve opening.

[0038] A linkage fit is formed between the rotating shaft 7 and the lower contact assembly 5 through the linkage part 71 and the linkage cooperation part 501 in the middle, and there are no other connecting parts between them. Compared with the existing structure that requires a middle connecting rod to be hinged to achieve linkage cooperation, the structure is simpler, and during installation, they are installed separately, so the assembly is more convenient and the process feasibility is higher.

[0039] In addition, the rotating shaft 7 only realizes linkage with the lower contact assembly 5 during closing. During opening, the rotating shaft 7 will reset and thus separate from the lower contact assembly 5, enabling the lower contact assembly 5 to be repelled downward by the electric repulsive force, increasing the opening distance, elongating the arc, improving the breaking performance, and having a small repelling resistance and a fast breaking speed.

[0040] Furthermore, an elastic member 13 capable of driving the lower contact assembly 5 to rotate downward is also provided between the lower contact assembly 5 and the bracket 12. During opening, in addition to the electric repulsive force, the lower contact assembly 5 can also receive the downward elastic force of the elastic member 13, thereby further improving the action speed of the lower contact assembly 5, further achieving fast opening, and improving the breaking speed.

[0041] Among them, the elastic member 13 is of a double torsion spring structure, which includes two spring bodies 131 and a U-shaped connecting rod 132 connecting the two spring bodies 131, and elastic rods 133 extend from both spring bodies 131.

[0042] The lower contact assembly 5 is rotatably installed at the upper end of the bracket 12 through a hinge shaft 11. The two spring bodies 131 of the elastic member 13 are sleeved outside the hinge shaft 11 and are respectively arranged on both sides of the lower contact support 52. The U-shaped connecting rod 132 abuts against the lower contact support 52, and the elastic rods 133 abut against the bracket 12.

[0043] The elastic member 13 with the above structure and its installation structure are not only convenient for installation and assembly, but also have balanced force and stable and reliable operation.

[0044] On both sides of the lower contact support 52, isolation covers 521 with a "C"-shaped opening at the lower end are integrally formed, and the elastic member 13 is correspondingly arranged inside the isolation covers 521. Since both the lower contact and the elastic member are electrified when opening and disconnecting, and the lower contact support 52 is usually made of an insulating material, it can play an insulating and isolating role to prevent breakdown between the lower contact assembly 5 and the upper contact assembly 6. The structure of setting the isolation covers 521 can further protect the elastic member 13 and prevent breakdown between the elastic member 13 and the upper contact assembly 6, which is safer and more reliable.

[0045] Further, a isolation boss 522 is formed downward at a position corresponding to the rear end of the isolation cover 521 on the lower contact support 52. The U-shaped connecting rod abuts against the isolation boss 522. The isolation boss 522 is in a "convex" shape. As an extension of the isolation cover 521, it further isolates the lower contact and the elastic member, and at the same time, the isolation boss 522 can position and fix the elastic member 13.

[0046] In addition, the bracket 12 is bent to form a "convex" shaped structure. An arc-shaped limiting groove 121 adapted to the elastic rod 133 is formed at the rear side of the shoulder position of the bracket 12. The elastic rod 133 abuts against the two shoulders of the bracket 12 and is correspondingly stuck in the arc-shaped limiting groove 121, making the overall installation of the elastic member more reliable and stable.

[0047] As Figures 8-9 shown, the arc extinguishing chamber 4 is arranged between the first terminal 3 and the lower contact assembly 5. An arc guiding member 15 is provided below the arc extinguishing chamber 4. One end of the arc guiding member 15 is connected to the first terminal 3, and the other end extends to the lower part of the lower contact assembly 5 and is bent towards the arc extinguishing chamber 4. When the lower contact assembly 5 is disconnected from the upper contact assembly, the arc on the lower contact assembly 5 can be quickly guided to the arc extinguishing chamber 4 through the arc guiding member 15, further improving the arc extinguishing performance and ensuring safe and reliable breaking.

[0048] As Figure 1 and Figures 10-12 shown, the face cover 2 is fixedly installed on the base 1, and an exhaust port 21 corresponding to the arc extinguishing chamber 4 is provided on the face cover 2. An arc isolation cover 14 that separates the arc extinguishing chamber 4 from the first terminal 3 is provided in the base 1. The arc isolation cover 14 includes a partition 141 and an exhaust passage 142 extending towards the first terminal 3. The extending length of the exhaust passage 142 is not less than the length dimension of the first terminal 3 in the corresponding direction and extends to the other side of the first terminal.

[0049] When the lower contact assembly 5 is disconnected from the upper contact assembly 6, after the arc is introduced into the arc extinguishing chamber 4 and eliminated, the generated gas can be discharged through the exhaust port 21 and the exhaust passage 142. On the basis of the original exhaust port 21, the exhaust passage 142 is further added, thereby effectively relieving the exhaust pressure at the upper exhaust port 31 and improving the overall performance.

[0050] The arc isolation cover 14 can effectively isolate the first terminal 3 and the arc extinguishing chamber 4 through the partition 141, and the exhaust passage 142 extends towards the first terminal 3 until the outer side position of the first terminal, so that after the arc extinguishing cover is increased with the exhaust function, it can still ensure its reliable isolation and arc isolation function.

[0051] The exhaust passage 142 includes an inlet passage and an outlet passage. The inlet passage has a constricted structure, with its inlet size larger than its outlet size. The inlet size is maximized as much as possible so that gas within a larger range can enter the inlet passage and then be discharged through the outlet passage, thereby further improving the exhaust effect.

[0052] At least one protruding blocking boss 143 is formed on the side wall of the exhaust passage 142. The blocking boss 143 makes the exhaust passage 22 have the effect of a turning passage. When the air flow passes through the blocking boss 143, it will be blocked by the blocking boss 143 and thus form a turn. This can prevent the direct injection of the air flow, isolate and block high-temperature particles, and effectively reduce the damage of the air flow to external equipment and circuits.

[0053] Two sets of the exhaust passages 142 are provided and are respectively arranged at both side positions of the partition plate 141, fitting against the side wall of the base 1. The overall layout is reasonable. While ensuring exhaust, it avoids blocking the first terminal 3 and facilitates the wiring operation of the first terminal 3.

[0054] During specific installation, the arc isolation cover 14 is directly inserted into the base 1 by means of plugging, and then the arc isolation cover 14 is pressed tightly by the face cover 2. The structure is simple and the installation is convenient.

[0055] Furthermore, a plurality of guiding grooves 144 are formed on the back surface of the partition plate 141. The guiding grooves 144 extend from the middle of the partition plate 141 towards the exhaust passage 142. The guiding grooves 144 can guide the air flow so that it can quickly pass through the exhaust passage 142 along the guiding grooves 144, further increasing the exhaust effect.

[0056] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0057] In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of the present invention, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0058] Dear technicians, please note that although the present invention has been described according to the above specific embodiments, the inventive concept of the present invention is not limited to this invention. Any modification using the inventive concept of the present invention will be included in the scope of protection of the patent right of this patent.

Claims

1. A molded case circuit breaker, comprising a base (1), a face cover (2), and a first terminal (3), an arc extinguishing chamber (4), a lower contact assembly (5), an upper contact assembly (6), a rotating shaft (7), an operating mechanism (8), a tripping mechanism (9), and a second terminal (10) disposed within the base (1); the lower contact assembly (5) is rotatably mounted on a bracket (12) fixed to the base (1) by a hinge shaft (11), the upper contact assembly (6) is mounted on the rotating shaft (7), and the rotating shaft (7) can drive the upper contact assembly (6) to actuate, connecting or disconnecting from the lower contact assembly (5). It is characterized in that: A linkage portion (71) is formed on the rotating shaft (7), the rear end of the lower contact assembly (5) extends rearward below the rotating shaft (7), and a linkage mating portion (501) corresponding to the linkage portion (71) is formed; an elastic member (13) capable of driving the lower contact assembly (5) to rotate downward is further provided between the lower contact assembly (5) and the bracket (12); during closing, the rotating shaft (7) can push the lower contact assembly (5) to rotate upward to be in contact with the upper contact assembly (6), and during opening, the lower contact assembly (5) separates from the rotating shaft (7) and can automatically rotate downward.

2. The molded case circuit breaker according to claim 1, wherein: The linkage portion (71) is of an arc-shaped structure.

3. The molded case circuit breaker according to claim 1, characterized in that: The elastic member (13) is of a double torsion spring structure, which includes two spring bodies (131) and a U-shaped connecting rod (132) connecting the two spring bodies (131), and elastic rods (133) extend from both spring bodies (131); the two spring bodies (131) of the elastic member (13) are sleeved outside the hinge shaft (11) and are respectively disposed on both sides of the lower contact assembly (5), the U-shaped connecting rod (132) abuts against the lower contact assembly (5), and the elastic rods (133) abut against the bracket (12).

4. The molded case circuit breaker according to claim 1, characterized in that: The lower contact assembly (5) includes a lower contact (51) and a lower contact support (52), the lower contact support (52) is sleeved outside the lower contact (51), and isolating covers (521) with a lower end opening in a "C" shape are integrally formed on both sides of the lower contact support (52), and the elastic member (13) is disposed within the isolating covers (521).

5. The molded case circuit breaker according to any one of claims 1-4, characterized in that: The face cover (2) is fixedly mounted on the base (1), and an exhaust port (21) corresponding to the arc extinguishing chamber (4) is provided on the face cover (2); An arc isolating cover (14) separating the arc extinguishing chamber (4) from the first terminal (3) is provided within the base (1), the arc isolating cover (14) includes a partition plate (141) and an exhaust passage (142) extending in the direction of the first terminal (3), and the exhaust passage (142) extends to the other side of the first terminal (3).

6. The molded case circuit breaker according to claim 5, characterized in that: The exhaust passage (142) includes an inlet passage and an outlet passage, and the inlet passage is of a reduced diameter structure, and its inlet size is larger than its outlet size.

7. The molded case circuit breaker according to claim 5, characterized in that: The side wall of the exhaust passage (142) is at least formed with a protruding blocking boss (143).

8. The molded case circuit breaker according to claim 5, characterized in that: The exhaust channels (142) are provided in two groups and are respectively arranged at both side positions of the partition plate (141). A plurality of guiding grooves (144) are formed on the back surface of the partition plate (141), and the guiding grooves (144) extend from the middle of the partition plate (141) towards the exhaust channels (142) on both sides.

9. The molded case circuit breaker according to claim 1, wherein: An arcing piece (15) is provided below the arc extinguishing chamber (4). One end of the arcing piece (15) is connected to the first terminal (3), and the other end extends below the lower contact assembly (5) and bends towards the arc extinguishing chamber (4).

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