Backup protection device for electronic molded case circuit breaker and electronic molded case circuit breaker

Abstract

A backup protection device for an electronic molded case circuit breaker includes a bracket, on which a mutual inductor, a U-shaped armature, and a U-shaped iron core are mounted. The U-shaped armature and the opening of the U-shaped iron core are opposite to each other to form a conductor hole. The U-shaped armature is rotatably mounted on the bracket via an elastic rotating mechanism. The U-shaped armature is provided with an impact portion for triggering the circuit breaker to trip. When the short-circuit current passing through the conductor magnetizes the U-shaped iron core and the magnetic force generated enables the U-shaped armature to overcome the elastic force of the elastic rotating mechanism, the U-shaped armature rotates toward the U-shaped iron core, and the impact portion of the U-shaped armature hits the circuit breaker to trip and cut off the power. An electronic molded case circuit breaker includes the above-mentioned backup protection device. The bracket of the backup device is provided with a traction rod connected to the tripping mechanism. The conductive plate connected between the moving contact and the terminal serves as a conductor and passes through the conductor hole. The backup protection device for an electronic molded case circuit breaker of the present invention has a simple structure, is easy to assemble, and occupies a small space in the circuit breaker.

Description

Technical Field

[0001] The present invention relates to the field of low-voltage electrical appliances, and in particular to a backup protection device of an electronic molded case circuit breaker and an electronic molded case circuit breaker. Background Art

[0002] Since the molded case circuit breaker with electronic release has multiple protection functions, adjustable rated current, stable action performance, high protection accuracy and other advantages, this type of circuit breaker is gradually becoming the mainstream trend of the development of molded case circuit breakers.

[0003] Compared to traditional thermal-magnetic products, electronic molded case circuit breakers (ECCBs) have significantly longer short-circuit tripping times due to limitations in their operating principle. This results in a prolonged arcing duration during short-circuit tripping, causing significant damage to both the breaker itself and the circuit it protects. Electronic molded case circuit breakers typically employ an electromagnetic backup protection device to compensate for this short-circuit. When a high short-circuit current flows through the circuit protected by the ECB, the backup protection device quickly trips the circuit breaker to provide short-circuit protection. When the short-circuit current in the circuit is not too high—that is, within 18 times the rated current (18 In), the short-circuit current is relatively low, and the long arcing duration does not cause significant damage. Therefore, short-circuit protection primarily relies on the electronic trip unit.

[0004] Currently, most backup protection devices applied to plastic case electronic molded case circuit breakers have a relatively complex structure, which not only makes assembly complicated but also requires a large space. Summary of the Invention

[0005] The object of the present invention is to overcome the defects of the prior art and provide a backup protection device for an electronic molded case circuit breaker and an electronic molded case circuit breaker with simple structure and high reliability.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A backup protection device for an electronic molded case circuit breaker includes a bracket, on which a mutual inductor, a U-shaped armature, and a U-shaped iron core are mounted. The U-shaped armature and the opening of the U-shaped iron core are opposed to each other to form a conductor hole for a conductor to pass through. The U-shaped armature is rotatably mounted on the bracket via an elastic rotating mechanism. The U-shaped armature is provided with an impact portion for triggering the circuit breaker to trip. When a short-circuit current passing through the conductor magnetizes the U-shaped iron core and the magnetic force generated enables the U-shaped armature to overcome the elastic force of the elastic rotating mechanism, the U-shaped armature rotates toward the U-shaped iron core, and the impact portion of the U-shaped armature impacts the trip mechanism, causing it to trip and cut off power.

[0008] Furthermore, the U-shaped core is installed above the U-shaped armature and the two have a partial overlapping area, the opening of the U-shaped core faces downward, the opening of the U-shaped armature faces upward, and the side of the U-shaped armature facing the U-shaped core is provided with an impact portion for impacting the traction rod.

[0009] Furthermore, the U-shaped iron core is sheet-shaped, and the opening of the U-shaped iron core is a trapezoid that is narrow at the top and wide at the bottom. The two side arms of the U-shaped iron core are both trapezoidal that are narrow at the bottom and wide at the top. The outer edges of the two side arms of the U-shaped iron core extend outward to form a locking protrusion that is locked into the bracket. The width of the locking protrusion gradually increases from bottom to top, so that the U-shaped iron core as a whole is a trapezoid that is narrow at the bottom and wide at the top.

[0010] Furthermore, the two side arms of the U-shaped armature are wedge-shaped and gradually become thinner from bottom to top. A collision portion is protruded from the upper part of one side arm of the U-shaped armature, and mounting holes for installing the elastic rotation mechanism are provided at the lower parts of the two side arms. The lower parts of the two side arms are connected by a linkage arm, and the linkage arm is located on the side away from the U-shaped iron core.

[0011] Furthermore, two side arms of the U-shaped armature are provided with stop protrusions at the lower part close to one side of the bracket, and the stop protrusions cooperate with the bracket to stop rotation.

[0012] Furthermore, the bracket is U-shaped as a whole, with a transformer mounting groove provided on one side of the bracket, an armature mounting portion provided on the other side of the bracket, and an iron core mounting groove provided between the armature mounting portion and the transformer mounting groove. The iron core mounting grooves are symmetrically arranged on the two side walls of the bracket and a fixing structure for fixing the U-shaped iron core is provided on the iron core mounting groove.

[0013] Furthermore, the armature mounting portion includes two oppositely arranged wing plates, a support platform for supporting the elastic rotation mechanism is provided between the two wing plates, an arc-shaped rotation groove is provided in the middle of the support platform, and a downward-opening U-shaped groove is provided at the lower part of the wing plate. The two side arms of the U-shaped armature are arranged on the outer sides of the two wing plates, and the elastic rotation mechanism of the U-shaped armature is installed in the U-shaped groove.

[0014] Furthermore, the distance between the two wing plates is less than or equal to the spacing of the openings of the U-shaped iron core.

[0015] Furthermore, the elastic rotation mechanism includes a torsion spring and a rotating shaft, the torsion spring is sleeved on the rotating shaft, both ends of the rotating shaft are rotatably supported on the bracket, and the U-shaped armature is provided with a mounting hole for the rotating shaft to pass through, one elastic arm of the torsion spring is against the linkage arm of the U-shaped armature, and the other elastic arm is against one side of the support platform.

[0016] An electronic molded case circuit breaker includes a backup device for the electronic molded case circuit breaker described above, wherein a traction rod connected to a tripping mechanism of the electronic molded case circuit breaker is provided above a bracket of the backup device, and a conductive plate connected between a moving contact and a terminal serves as a conductor and passes through a conductor hole of the bracket. When a short-circuit current passing through the conductive plate causes the magnetic force generated by the U-shaped iron core to cause the U-shaped armature to overcome the elastic force of the elastic rotation mechanism, the impact portion of the U-shaped armature impacts the traction rod, causing the tripping mechanism of the circuit breaker to trip and cut off power.

[0017] The backup protection device for an electronic molded case circuit breaker of the present invention comprises a mutual inductor and a U-shaped iron core mounted on a bracket. The U-shaped armature is rotatably mounted on the bracket via an elastic rotating mechanism and passes through a conductive plate within a conductor hole surrounded by the U-shaped iron core and the U-shaped armature. The entire device has a simple structure, is easy to assemble, and occupies a small space in the circuit breaker.

[0018] The electronic molded case circuit breaker of the present invention is provided with a backup protection device which has a simple structure and occupies a small space, which is beneficial to the miniaturized design of the electronic molded case circuit breaker.

[0019] In addition, the U-shaped iron core, U-shaped armature and mutual inductor are installed on the bracket at the same time. The U-shaped iron core is located above the wire plate and is vertically clamped to the bracket, reducing the space occupied by various parts in the circuit breaker; a wing plate is provided on the bracket to prevent the U-shaped armature from swinging left and right during movement. The bracket is supported by a rotating shaft to keep the distance between the U-shaped armature and the U-shaped iron core fixed, ensuring performance stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the backup protection device of the electronic molded case circuit breaker of the present invention;

[0021] Figure 2 This is a schematic diagram of the U-shaped iron core structure of the backup protection device of the electronic molded case circuit breaker of the present invention;

[0022] Figure 3 yes Figure 2 The main view;

[0023] Figure 4 This is a schematic diagram of the U-shaped armature structure of the backup protection device of the electronic molded case circuit breaker of the present invention;

[0024] Figure 5 Schematic diagram of the support structure of the backup protection device of the electronic molded case circuit breaker of the present invention (three);

[0025] Figure 6 This is a side view of a bracket of a backup protection device for an electronic molded case circuit breaker of the present invention;

[0026] Figure 7This is a structural diagram (including the base) of the backup protection device of the electronic molded case circuit breaker of the present invention applied to the circuit breaker;

[0027] Figure 8 This is a structural diagram of the backup protection device of the electronic molded case circuit breaker of the present invention applied to the circuit breaker (excluding the base). DETAILED DESCRIPTION

[0028] The following is combined with Figures 1 to 8 The following embodiments further illustrate the specific implementation of the backup protection device for the electronic molded case circuit breaker of the present invention. The backup protection device for the electronic molded case circuit breaker of the present invention is not limited to the description of the following embodiments.

[0029] A backup protection device for an electronic molded case circuit breaker includes a bracket 1, on which a mutual inductor 4, a U-shaped armature 5, and a U-shaped iron core 6 are installed. The U-shaped armature 5 and the opening of the U-shaped iron core 6 are opposite to each other to form a conductor hole 12. The U-shaped armature 5 is rotatably mounted on the bracket 1 by an elastic rotating mechanism. The U-shaped armature 5 is provided with an impact portion 51 for triggering the circuit breaker to trip. When the short-circuit current passing through the conductor magnetizes the U-shaped iron core 6 and the magnetic force generated enables the U-shaped armature 5 to overcome the elastic force of the elastic rotating mechanism, the U-shaped armature 5 rotates toward the U-shaped iron core 6, and the impact portion 51 of the U-shaped armature 5 impacts the tripping mechanism to trip and cut off the power.

[0030] The backup protection device for an electronic molded case circuit breaker of the present invention comprises a mutual inductor 4 and a U-shaped iron core 6 mounted on a bracket 1. The U-shaped armature 5 is rotatably mounted on the bracket 1 via an elastic rotating mechanism and passes through a conductive plate 2 within a conductor hole 12 defined by the U-shaped iron core 6 and the U-shaped armature 5. The entire device has a simple structure, is easy to assemble, and occupies a small space in the circuit breaker.

[0031] like Figure 1 As shown, a backup protection device for an electronic molded case circuit breaker includes a bracket 1 and a conductive plate 2 (see Figure 7 or Figure 8), a traction rod 3 connected to the tripping mechanism of the electronic molded case circuit breaker is provided above the bracket 1, and the bracket 1 is installed with a mutual inductor 4, a U-shaped armature 5 and a U-shaped iron core 6, the U-shaped armature 5 and the opening of the U-shaped iron core 6 are opposite to each other to form a conductor hole 12, the conductive plate 2 is used as a conductor to pass through the mutual inductor 4 and the conductor hole 12 and is connected to the moving contact in the circuit breaker, and the conductive plate 2 is preferably kept perpendicular to the U-shaped iron core 6; the U-shaped armature 5 is rotatably mounted on the bracket 1 through an elastic rotation mechanism, and the U-shaped armature 5 is provided with a striking portion 51 for striking the traction rod 3 of the circuit breaker, and the traction rod 3 of the circuit breaker is used to trigger the tripping mechanism of the circuit breaker to trip and cut off the power; when the short-circuit current passing through the conductive plate 2 causes the U-shaped iron core 6 to be magnetized and the magnetic force generated can enable the U-shaped armature 5 to overcome the elastic force of the elastic rotation mechanism, the U-shaped armature 5 rotates toward the U-shaped iron core 6, and the striking portion 51 of the U-shaped armature 5 strikes the traction rod 3 to cause the tripping mechanism to trip and cut off the power.

[0032] like Figure 1 As shown, the U-shaped core 6 is installed above the U-shaped armature 5 and the two have a partial overlapping area, which is located at the upper part of the U-shaped armature 5 and the lower part of the U-shaped core 6. The opening of the U-shaped core 6 faces downward, and the opening of the U-shaped armature 5 faces upward. The side of the U-shaped armature 5 facing the U-shaped core 6 is provided with a striking portion 51 for striking the traction rod 3. When a large short-circuit current passes through the conductive plate 2, the U-shaped core 6 is magnetized, and the upper part of the U-shaped armature 5 overcomes the elastic force of the elastic rotation mechanism under the action of the magnetic force and moves toward the U-shaped core. 6, which is shown as clockwise rotation in the figure. After the impact portion 51 on the U-shaped armature 5 hits the force-bearing portion of the draw rod 3, the draw rod 3 rotates counterclockwise to drive the tripping mechanism of the circuit breaker to trip and cut off the power. When a small short-circuit current flows through the conductive plate 2, although the U-shaped core 6 can also be magnetized, the magnetic force between the U-shaped core 6 and the U-shaped armature 5 is insufficient to enable the U-shaped armature 5 to overcome the elastic force of the elastic rotation mechanism. Therefore, the U-shaped armature 5 will not rotate to hit the draw rod 3 to trip the tripping mechanism of the circuit breaker and cut off the circuit.

[0033] like Figure 2 、 3 As shown, the U-shaped core 6 is sheet-shaped, and the opening of the U-shaped core 6 is preferably a trapezoid that is narrow at the top and wide at the bottom. Of course, the opening of the U-shaped core 6 can also be a square opening or an opening that is approximately arc-shaped. The two side arms of the U-shaped core 6 are both trapezoidal, narrow at the bottom and wide at the top. The outer edges of the two side arms of the U-shaped core 6 extend outward to form a locking protrusion 61 that is snapped into the bracket 1. The width of the locking protrusion 61 gradually increases from bottom to top, so that the U-shaped core 6 as a whole is a trapezoid that is narrow at the bottom and wide at the top. This overall trapezoidal U-shaped core 6 is conducive to being snapped onto the bracket 1 to prevent the U-shaped core 6 from falling off the bracket 1.

[0034] like Figure 4As shown, the two side arms of the U-shaped armature 5 are wedge-shaped, tapering from bottom to top. A striking portion 51 is protruding from the upper portion of one side arm of the U-shaped armature 5. The side arm with the striking portion 51 is preferably taller than the side arm without the striking portion 51 to facilitate the cooperation between the striking portion 51 and the force-bearing portion of the drawbar 3. Mounting holes 53 for mounting an elastic rotation mechanism are provided at the lower portions of the two side arms. The lower portions of the two side arms are connected by a linkage arm 52, which is located on the side away from the U-shaped core 6. To reduce excessive rotation of the U-shaped armature 5, stop protrusions 54 are preferably provided on the lower portions of the two side arms of the U-shaped armature 5 near the bracket 1. The stop protrusions 54 cooperate with the bracket 1 to stop rotation. The stop protrusions 54 are formed by protruding from the lower edges of the two side walls of the U-shaped armature 5.

[0035] like Figure 5 、 6 As shown, the bracket 1 is generally in an upwardly open U-shape, with a transformer mounting groove 17 provided on one side of the bracket 1, and an armature mounting portion provided on the other side of the bracket 1. An iron core mounting groove 11 is provided between the armature mounting portion and the transformer mounting groove 17. The iron core mounting grooves 11 are symmetrically arranged on the two side walls of the bracket 1 and a fixing structure for fixing the U-shaped iron core 6 is provided on the iron core mounting groove 11. Figure 6 The fixing structure shown in the figure is a conductor hole 12. By providing the conductor hole 12 on the side wall of the core mounting slot 11, the locking protrusions 61 on the outer edges of the two side arms of the U-shaped core 6 can be locked into the conductor hole 12 to prevent the U-shaped core 6 from falling. Other forms of fixing structures can also be provided in the core mounting slot 11. Of course, the core mounting slot 11 can also be omitted on the bracket 1, and the U-shaped core 6 can be connected to the bracket 1 through other connecting structures.

[0036] The armature mounting portion, located on one side of the bracket 1, includes two opposing wing plates 13. The spacing between the wing plates 13 is preferably less than or equal to the spacing between the openings of the U-shaped core 6. A support platform 15 for supporting the elastic rotation mechanism is located between the two wing plates 13. The center of the support platform 15 is provided with an arc-shaped rotation groove 16. The center of the elastic rotation mechanism is supported and rotated within the rotation groove 16. A downwardly open U-shaped groove 14 is provided at the bottom of the wing plates 13. The U-shaped groove 14 allows the elastic rotation mechanism to pass through. The two side arms of the U-shaped armature 5 are arranged on the outside of the two wing plates 13 to limit the left and right swing of the U-shaped armature 5 during rotation, preventing the impact portion 51 from accurately impacting the force-bearing portion of the drawbar 3, resulting in a delayed release. The elastic rotation mechanism of the U-shaped armature 5 is installed within the U-shaped groove 14 of the wing plates 13.

[0037] like Figure 1As shown, the elastic rotation mechanism for rotatably mounting the U-shaped armature 5 on the bracket 1 includes a torsion spring 72 and a rotating shaft 71, wherein the torsion spring 72 is sleeved on the rotating shaft 71, and both ends of the rotating shaft 71 are rotatably supported on the bracket 1, and a mounting hole 53 for the rotating shaft 71 to pass through is provided on the U-shaped armature 5. The U-shaped armature 5 is rotatably supported on the bracket 1 by the rotating shaft 71, so that the distance between the U-shaped armature 5 and the U-shaped iron core 6 is fixed, thereby maintaining the stability of the performance; further, one elastic arm of the torsion spring 72 is abutted against the linkage arm 52, and the other elastic arm is abutted against one side of the support platform 15 between the two wing plates 13.

[0038] like Figure 1 、 7 As shown in FIG8 , the number of brackets 1 is three, and three brackets 1 are set for use on a three-pole circuit breaker. Therefore, the number of brackets 1 is related to the model of the circuit breaker. For example, when used on a two-pole circuit breaker, the number of brackets 1 is two, and when used on a four-pole circuit breaker, the number of brackets 1 is four, and so on.

[0039] An electronic molded case circuit breaker includes the backup device of the electronic molded case circuit breaker mentioned above. A traction rod 3 connected to the tripping mechanism of the electronic molded case circuit breaker is provided above the bracket 1 of the backup device. A conductive plate 2 connected between the moving contact and the terminal serves as a conductor and passes through the conductor hole 12 of the bracket 1. When the short-circuit current passing through the conductive plate 2 causes the magnetic force generated by the U-shaped iron core 6 to cause the U-shaped armature 5 to overcome the elastic force of the elastic rotation mechanism, the impact portion 51 of the U-shaped armature 5 impacts the traction rod 3, causing the tripping mechanism of the circuit breaker to trip and cut off the power.

[0040] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A backup protection device for an electronic molded case circuit breaker, comprising a bracket (1), characterized in that: A transformer mounting groove (17) is provided on one side of the bracket (1), an armature mounting portion is provided on the other side of the bracket (1), and an iron core mounting groove (11) is provided between the armature mounting portion and the transformer mounting groove (17). The bracket (1) is provided with a transformer (4), a U-shaped armature (5) and a U-shaped iron core (6). The openings of the U-shaped armature (5) and the U-shaped iron core (6) are opposite to each other to form a conductor hole (12) for a conductor to pass through. The U-shaped armature (5) is rotatably mounted on the bracket (1) through an elastic rotating mechanism. The U-shaped armature (5) is provided with an impact portion (51) for triggering the tripping of a circuit breaker. When a short-circuit current passing through the conductor magnetizes the U-shaped iron core (6), the magnetic force generated by the magnetization can cause the U-shaped armature (5) to overcome the elastic force of the elastic rotating mechanism, and the U-shaped armature (5) rotates toward the U-shaped iron core (6). The impact portion (51) of the U-shaped armature (5) impacts and causes the circuit breaker to trip and power off.

2. The backup protection device for an electronic molded case circuit breaker according to claim 1, characterized in that: The U-shaped iron core (6) is installed above the U-shaped armature (5) and the two have a partial overlapping area, the opening of the U-shaped iron core (6) faces downward, the opening of the U-shaped armature (5) faces upward, and the side of the U-shaped armature (5) facing the U-shaped iron core (6) is provided with a collision portion (51) for striking the traction rod (3).

3. The backup protection device for an electronic molded case circuit breaker according to claim 1, characterized in that: The U-shaped iron core (6) is in the form of a sheet. The opening of the U-shaped iron core (6) is in the form of a trapezoid with a narrow top and a wide bottom. Both side arms of the U-shaped iron core (6) are in the form of a trapezoid with a narrow bottom and a wide top. The outer edges of the two side arms of the U-shaped iron core (6) extend outward to form a locking protrusion (61) that is locked into the bracket (1). The width of the locking protrusion (61) gradually increases from bottom to top, so that the U-shaped iron core (6) as a whole is in the form of a trapezoid with a narrow bottom and a wide top.

4. The backup protection device for an electronic molded case circuit breaker according to claim 1, characterized in that: The two side arms of the U-shaped armature (5) are wedge-shaped and gradually become thinner from bottom to top. The upper part of one side arm of the U-shaped armature (5) is provided with a protruding impact portion (51). The lower parts of the two side arms are provided with mounting holes (53) for mounting an elastic rotation mechanism. The lower parts of the two side arms are connected by a linkage arm (52). The linkage arm (52) is located on a side away from the U-shaped iron core (6).

5. The backup protection device for an electronic molded case circuit breaker according to claim 4, characterized in that: The two side arms of the U-shaped armature (5) are provided with stop protrusions (54) at the lower part of one side close to the bracket (1), and the stop protrusions (54) cooperate with the bracket (1) to stop rotation.

6. The backup protection device for an electronic molded case circuit breaker according to claim 2, characterized in that: The bracket (1) is U-shaped as a whole, the iron core installation grooves (11) are symmetrically arranged on two side walls of the bracket (1), and a fixing structure for fixing the U-shaped iron core (6) is provided on the iron core installation grooves (11).

7. The backup protection device for an electronic molded case circuit breaker according to claim 6, characterized in that: The armature mounting portion includes two wing plates (13) arranged opposite to each other, a support platform (15) for supporting the elastic rotation mechanism is provided between the two wing plates (13), an arc-shaped rotation groove is provided in the middle of the support platform (15), and a U-shaped groove (14) open downward is provided at the lower part of the wing plates (13), two side arms of the U-shaped armature (5) are arranged on the outside of the two wing plates (13), and the elastic rotation mechanism of the U-shaped armature (5) is installed in the U-shaped groove (14).

8. The backup protection device for an electronic molded case circuit breaker according to claim 7, characterized in that: The distance between the two wing plates is less than or equal to the spacing of the openings of the U-shaped iron core (6).

9. The backup protection device for an electronic molded case circuit breaker according to claim 7, characterized in that: The elastic rotation mechanism comprises a torsion spring (72) and a rotating shaft (71), wherein the torsion spring (72) is sleeved on the rotating shaft (71), and both ends of the rotating shaft (71) are rotatably supported on the bracket (1), and a mounting hole (53) for the rotating shaft (71) to pass through is provided on the U-shaped armature (5), and one elastic arm of the torsion spring (72) abuts against the linkage arm (52) of the U-shaped armature (5), and the other elastic arm abuts against one side of the support platform (15).

10. An electronic molded case circuit breaker, characterized in that: The invention comprises a backup protection device for an electronic molded case circuit breaker as claimed in any one of claims 1 to 9, wherein a traction rod (3) connected to a tripping mechanism of the electronic molded case circuit breaker is provided above a bracket (1) of the backup protection device, and a conductive plate (2) connected between a moving contact and a terminal is passed through a conductor hole (12) of the bracket (1) as a conductor, and when a short-circuit current passing through the conductive plate (2) causes the magnetic force generated by the U-shaped iron core (6) to cause the U-shaped armature (5) to overcome the elastic force of the elastic rotating mechanism, the impact portion (51) of the U-shaped armature (5) impacts the traction rod (3) to cause the tripping mechanism of the circuit breaker to trip and cut off the power.

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