CN201503830U - Selective tripping device for low voltage circuit breaker - Google Patents

Abstract

The utility model discloses a selective tripping device for a low-voltage circuit breaker, which comprises conductors of three electrodes, an insulating case and an adjusting piece fixed on the insulating case. The adjusting rod is installed parallel to the side, and the two ends of the adjusting rod are suspended on the adjusting part. There are three pendant rods and one adjustable rod on the adjusting rod; The fixed armature and the movable armature, the fixed armature is fixedly installed on the conductor, the lower part of the movable armature can pivot; the upper end of the tension spring is hung on the pendant rod, the lower end is connected to the movable armature, and the upper end of the adjustable rod extends into the groove at the lower part of the knob. The utility model forms an air gap between the fixed armature and the movable armature. When the current exceeds the corresponding threshold value, the movable armature moves from the static position to the fixed armature to realize the tripping function. Different tension can be obtained by adjusting the tension spring and the adjustable rod. The tripping current is high, and the tripping action is reliable.

Description

Selective tripping device for low voltage circuit breaker

technical field

The utility model relates to a low-voltage electrical equipment, in particular to a tripping device of a multi-pole low-voltage circuit breaker, in particular to a device with a magnetic tripping and a thermal tripping on each pole.

Background technique

When the low-voltage circuit breaker detects the passage of overcurrent in the main circuit system, its tripping unit generates a tripping action to protect the circuit system and various components in the main circuit from damage. The tripping unit includes a magnetic tripping unit And the thermal trip unit, the magnetic trip unit generally adopts the oil cup type or the magnetic yoke type structure, the oil cup type magnetic trip unit adopts the upper and lower armatures, and there is a spring between the armatures. When the short-circuit current passes, the upper armature is sucked, so that The trip lever moves and the mechanism trips. Since the magnetic trip unit sets a fixed threshold value, it cannot be adjusted during use and has no selectivity. Due to structural limitations of the yoke-type magnetic trip unit, the gap or the spring force it receives cannot be adjusted. In the thermal trip unit, since the trip rod cannot move in the axial direction, the distance between the trip rod and the bimetal strip is fixed, so the thermal trip unit also has no selectivity.

Contents of the invention

The purpose of the utility model is to provide a selective magnetic tripping and thermal tripping device on each electrode, so as to realize the selective protection of the low-voltage circuit breaker.

The technical scheme adopted by the utility model is: a conductor including three electrodes, an insulating case and an adjusting piece fixed on the insulating case, the tripping rod is installed on the insulating case, and the regulating rod is installed in parallel beside the tripping rod. The two ends are suspended on the adjusting piece, and the adjusting rod has three pendant rods and one adjustable rod; a fixed armature and a moving armature are respectively arranged between the adjusting rod and the three conductors, and there is a gap between them, and the fixed armature is fixed. Installed on the conductor, the lower part of the movable armature can pivot; the upper end of the extension spring is hung on the pendant rod, the lower end is connected to the movable armature, and the upper end of the adjustable rod extends into the groove at the lower part of the knob.

The spring force of the extension spring is greater than the magnetic force generated by the rated current between the fixed armature and the movable armature and smaller than the magnetic force generated by the short-circuit current.

One end of the energy storage mechanism is connected with the trip bar, and the other end is connected with the circuit breaker operating mechanism.

The utility model adds a fixed armature and a moving armature on the basis of the existing magnetic tripping and thermal tripping devices, so that an air gap is formed between the fixed armature and the moving armature. The position moves toward the fixed armature to realize the tripping function. At the same time, different tripping currents can be obtained by adjusting the tension spring, adjustable rod, etc., and the tripping action is reliable.

Description of drawings

The utility model will be described in further detail below by means of the accompanying drawings and specific embodiments.

Fig. 1 is a three-dimensional structure diagram of the present invention;

Fig. 2 is an enlarged schematic diagram of the selective tripping device after removing the insulating case 10 in Fig. 1;

FIG. 3 is a partial view of a pole tripping device in FIG. 2. FIG.

In the figure: 1. Conductor; 2. Bracket; 3. Moving armature; 4. Fixed armature; 6. Adjusting rod; 7. Tripping rod; 8. Knob; 9. Knob; 12. Pendant rod; 13. Adjustable rod; 14. Locking lever; 15. Joystick; 16. Adjustable screw; 17. Bimetal sheet; 19. Energy storage mechanism;

Detailed ways

As shown in Figure 1-2, the low-voltage circuit breaker is composed of three pole conductors 1, an insulating case 10, an adjustment member 23 and a tripping device inside it. In the load position, the circuit breaker is closed; in the tripping position, the low-voltage circuit breaker The contact automatically disconnects the conductor 1 for carrying the current flowing through each pole, and the trip bar 7 in the trip device is installed in the bearing on the insulating case 10 and rotates between the load position and the trip position. One end of the energy storage mechanism 19 with a striker is connected to the trip bar 7, and the other end is connected to the circuit breaker operating mechanism. When the tripping device detects a short-circuit current, the energy storage mechanism 19 disconnects the circuit breaker operating mechanism. The lower part of the bimetal strip 17 is riveted on the conductor 1, and the upper part is close to the trip bar 7. When an overload current passes through and lasts for a period of time, the conductor 1 acts as a heat source for the bimetal strip 17 in the thermal tripping device, causing the bimetal strip 17 to bend under heat. Drive the trip bar 7 and release the energy storage mechanism 19 to trip the circuit breaker. The upper part of the knob 8 protrudes out of the adjustment part 23, and the lower end of the knob 8 extends into the corresponding groove on the trip rod 7. When the knob 8 is rotated, the knob 8 drives the trip rod 7 to move laterally. When the trip rod 7 moves to Selective thermal protection can be achieved by selecting a specific position.

As shown in Figure 2-3, the adjustment rod 6 is installed in parallel beside the trip rod 7, and the two ends of the adjustment rod 6 are suspended on the adjustment part 23, which is fixed on the insulating shell 10, and the adjustment rod 6 and the trip Rod 7 is also located above the three-pole magnetic tripping device, and adjustment rod 6 has three pendant rods 12 and an adjustable rod 13 .

A fixed armature 4 and a movable armature 3 are respectively arranged between the adjusting rod 6 and the three conductors 1, and the fixed armature 4 and the movable armature 3 are arranged oppositely so that a gap is formed between the fixed armature 4 and the movable armature 3, and the fixed armature 4 is fixedly installed on the on conductor 1. The lower part of the movable armature 3 is installed in a gap at the base of the bracket 2 of the circuit breaker, so that the gap forms the rotating shaft of the movable armature 3 to realize the pivoting structure of the lower part of the movable armature 3, and the movable armature 3 can be used for limited pivoting. In this way, The current in the conductor 1 forms an electromagnetic field in the air gap between the fixed armature 4 and the movable armature 3. When the current intensity exceeds a predetermined tripping threshold, the movable armature 3 is attracted to the pole surface of the fixed armature 4. An adjustable screw 16 is arranged beside the movable armature 3 , the movable armature 3 is pressed against the adjustable screw 16 , and the adjustable screw 16 is used to adjust the gap between the movable armature 3 and the fixed armature 4 .

Each electrode is provided with a tension spring 11, the upper end of the tension spring 11 is hung on the pendant rod 12, the lower end of the tension spring 11 is connected to the moving armature 3, the tension spring 11 is used to provide the restoring force of the moving armature 3, and the The movable armature 3 is biased to an isolated rest position to obtain a maximum air gap between the polar faces of the movable armature 3 and the fixed armature 4 . The lower end of the adjustable rod 13 on the adjustment rod 6 is connected to the adjustment rod 6, and the upper end extends into the groove at the bottom of the knob 9, and the upper part of the knob 9 stretches out of the adjustment member 23. When the knob 9 is rotated, the groove on the knob 9 drives the adjustable When the rod 13 rotates, the adjusting rod 6 rotates, so that the pendant rod 12 on the adjusting rod 6 adjusts the extension spring 11, changes the spring force of the extension spring 11, and realizes selective magnetic tripping. There are three joysticks 15 on the trip rod 7, the upper end of the joystick 15 is connected to the trip rod 7, the lower end is located beside the corresponding movable armature 3, and there is a preset distance between the movable armature 3, when the movable armature 3 When attracted to the polar surface of the fixed armature 4 by magnetic force, the moving armature 3 drives the joystick 15 . There is also a locking lever 14 on the tripping rod 7, the lower end of the locking lever 14 is connected to the tripping rod 7, and the upper end is connected to the storage mechanism 19, which is used to lock or release the energy at the load position and the tripping position respectively. Storage mechanism 19 .

The working process of the selective magnetic trip device on each of the above poles is as follows:

In the air gap between the fixed armature 4 and the moving armature 3, the rated current of the conductor 1 produces a magnetic force, and the pulling force of the extension spring 11 is designed to be larger than the magnetic force, and the moving armature 3 is pressed on the adjustable screw 16. The trip bar 7 remains stationary in the loaded position and the locking lever 14 locks the mechanism.

When a short-circuit current occurs in the conductor 1, the magnetic attraction in the air gap between the fixed armature 4 and the moving armature 3 is designed to be greater than the tension of the extension spring 11, causing the moving armature 3 to pivot to the direction of the fixed armature 4. During the movement, the tension spring 11 is stretched, and the following two situations will occur after stretching:

1. If the short-circuit current disappears in the circuit, the moving armature 3 with the tension spring 11 prevents it from continuing to move under the tension of the tension spring 11, and the moving armature 3 does not contact the joystick 15 on the trip rod 7, and the joystick 15 remains still on the loaded position.

2. If the short-circuit current still exists, the magnetic attraction in the air gap makes the movable armature 3 continue to pivot to the end position, and presses against the polar surface of the fixed armature 4. , and turn the trip bar 7 to the trip position, and lock the lever 14 to release the mechanism to disconnect the circuit breaker.

In the above two cases, the extension spring 11 plays the role of preventing the moving armature 3, but when the current exceeds the threshold value corresponding to the calibration of the extension spring 11, the moving armature 3 will move from the rest position to the end position, and the extension spring 11 can Adjustable, the adjustment rod 6 can adjust the calibration of the extension spring 11 to obtain different tripping currents.

Claims (6)

1. A selectable tripping device for a low-voltage circuit breaker, comprising a conductor (1) of three electrodes, an insulating case (10) and an adjusting member (23) fixed on the insulating case (10), characterized in that: The trip rod (7) is arranged on the insulating case (10), and the adjustment rod (6) is arranged in parallel beside the trip rod (7). The two ends of the adjustment rod (6) are suspended on the adjustment piece (23), and the adjustment rod (6) has three pendant rods (12) and an adjustable rod (13); between the adjustment rod (6) and the three conductors (1), each is provided with a fixed armature (4) that is opposite to each other and has a gap therebetween. ) and the moving armature (3), the fixed armature (4) is fixedly installed on the conductor (1), and the lower part of the moving armature (3) is a pivoting structure; the upper end of the tension spring (11) is hung on the pendant rod (12), and the lower end Be connected on the movable armature (3), and the upper end of the adjustable rod (13) stretches in the groove of the knob (9) bottom. 2. The optional tripping device of low-voltage circuit breaker according to claim 1, characterized in that: the spring force of the tension spring (11) is greater than that generated by the rated current between the fixed armature (4) and the moving armature (3). The magnetic force is smaller than the magnetic force generated by the short-circuit current. 3. The optional tripping device for a low-voltage circuit breaker according to claim 1, characterized in that: one end of the energy storage mechanism (19) is connected to the trip rod (7), and the other end is connected to the circuit breaker operating mechanism. The lower part of the metal sheet (17) is connected on the conductor (1), the upper part is close to the trip bar (7), and the lower end of the knob (8) stretches into the corresponding groove on the trip bar (7). 4. The optional tripping device for low-voltage circuit breaker according to claim 1, characterized in that: there are three joysticks (15) on the trip rod (7), and the lower ends of the joysticks (15) are located at the corresponding Next to the moving armature (3), and has a preset distance from the moving armature (30). 5. The selective tripping device for low-voltage circuit breaker according to claim 1, characterized in that: the lower end of the locking lever (14) is connected to the trip rod (7), and the upper end is connected to the storage mechanism (19). 6. The selective tripping device for low-voltage circuit breaker according to claim 1, characterized in that: the movable armature (3) presses against the adjustable screw (16) beside it.

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