JPH05135679A - Resetting mechanism for circuit-breaker small-force tripping device - Google Patents

Abstract

PURPOSE:To stabilize resetting forces by mounting rollers at the end of a reset lever, and actuating the resetting mechanism while converting rotary motion of the lever into rectilinear motion, and pushing a moving iron core down from both sides. CONSTITUTION:The attracting force of a permanent magnet 31 is temporalily weakened by a current fed to a coil 37 from a separately provided controller, and a compression spring 36 moves a moving iron core 33 away from a fixed iron core 32 together with a rod 34 and then the moving iron core 33 is pushed upward. A link 82 rotates a reset lever 81 counterclockwise about a shaft 89 and a roller 100 pushes the moving iron core 33 down and the moving iron core 33 is moved downward while the spring 36 is compressed and then the moving iron core 33 is attracted to the fixed iron core 32 by the permanent magnet 31. As the moving iron core 32 is moved downward, the bearings of columns 102, 101 are guided. Since the current of the coil 53 is zero, the moving iron core 33 is attracted and held to the fixed iron core 32 by the permanent magnet 31 even if the lever 81 is restored, and thus resetting is completed. The moving iron core is reset while being balanced horizontally by two rollers, so that the action of the mechanism is stabilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trip mechanism for a circuit breaker used for electric power.

[0002]

2. Description of the Related Art FIG. 5 is a view showing a conventional trip device. Although FIG. 5 shows the apparatus alone for the sake of easy understanding, it is originally used by incorporating it in FIG. In this figure, 31 is a permanent magnet, and fixed iron cores 32 are attached to both sides thereof. A movable iron core 33 is attached so as to be able to contact the fixed iron core 32. 34 is a trip rod, a permanent magnet
It is arranged so that it penetrates through 31, and the flange part of the upper part engages with the lever 35 attached to the trip pin 9. The trip pin 9 is the same as that shown in FIG. 36 is a compression coil spring, 37 is a coil attached to a fixed iron core, 38
Is the case for the small force trip device. FIG. 7 is a diagram showing the structure of the reset portion of FIG. In this figure, the trip pin 9 and the case 38 are the same as those shown in FIG.
39 is a reset lever, and 40 is a leaf spring, which is attached to the tip of the reset lever 39 as shown in the figure. Reference numeral 41 is a lever attached to the shaft 18 and is integrated with the pole shaft lever 4 of FIG.

Next, the operation of the conventional tripping device reset mechanism will be described. The small-force trip device shown in FIG. 5 is a trip device of the type that operates with a small amount of energy. The movable iron core 33 is always held by a permanent magnet 31, and the coil for tripping the circuit breaker.
The circuit breaker is opened by passing a current through 37, and when the circuit breaker is opened, the small-force trip device is reset to the state before the operation. That is, when the circuit breaker is turned on, FIG.
The movable iron core 33 is kept attracted to the fixed iron core 32 by the magnetic flux of the permanent magnet 31, as shown in Fig.
There is a gap between 34 and lever 35. Lever in this state
35 does not receive the force of the trip lever 34 of the small-force trip device, the trip pin 9 and the trip latch 7 are kept in the engaged state as shown in FIG. 8, and the breaker is kept in the closed state.

Next, when tripping the circuit breaker, as shown in FIG.
A signal (current) is passed from another control device to the coil 37 of the small-force trip device, and the magnetic flux of the coil 37 temporarily cancels the magnetic flux of the permanent magnet 31 to weaken the attraction force on the fixed iron core side. The spring 36 pushes down the movable iron core. By this operation, the trip rod 34 moves downward, kicks the lever 35, and rotates the trip pin 9 counterclockwise as shown in FIG. 6 to disengage the trip latch 7 shown in FIG. 8 and trip the circuit breaker. .. The small force trip device is reset at the time of this circuit breaker opening operation, and the movement of the movable contactor 2 shown in FIG. 8 in the counterclockwise direction about the axis of 17 causes the pole shaft lever 4 to rotate clockwise, This movement is the movement of the lever 41 in FIG. 7, and it also rotates clockwise, and the reset lever
The leaf spring 40 at the tip of 39 is pushed up and the reset lever 39 rotates counterclockwise about the shaft 42, the tip of the reset lever 39 lifts the trip rod 34, and the compression coil spring 36
The movable iron core 33 is attracted to the fixed iron core 32 again by the permanent magnet 31 while compressing. When the circuit breaker is in the tripped state,
The trip rod 34 remains lifted by the reset lever 39.

[0005]

As described above, in the conventional mechanism, when the breaker is opened, a part of the opening force is converted into the force of the leaf spring to reset the small force trip device. There was a problem. (1) Reset operation is not stable. At the time of reset, the reset lever lifts the brim portion of the trip rod only on one side, and has a structure that easily causes reset failure. (2) The reset stroke is not constant. The reset operation is performed by the difference between the leaf spring force and the tripping force, and it is considered that the reset force and the stroke may change when the balance of the forces is lost due to deterioration of the spring. As described above, the conventional mechanism has a drawback that the reset operation is stable and cannot be applied to a circuit breaker that requires a trip device without deterioration.

[0006]

In the tripping device reset mechanism according to the present invention, in order to solve the above, the structure on the reset driving side is a rotary type by a roller, and the rotary motion is converted into a linear motion. The movement stroke of is always constant. Further, the mechanical force transmitted from the driving side is transmitted to both sides of the movable iron core. The reset operation is performed when the roller reciprocates, that is, twice.

[0007]

Since the tripping device reset mechanism according to the present invention is constructed as described above, it is possible to take out the rotary motion of the driving side as a linear motion and compress the spring, and the roller reciprocates once on both sides of the movable iron core. A reset operation can be performed. As a result, the dimension for compressing the spring is always constant, and the stability when resetting the movable core is increased.

[0008]

【Example】

Example 1. An embodiment of the present invention will be described below. 2 shows a state in which the small force trip device operates, FIG. 3 shows a state in which the small force trip device is being reset, and FIG. 4 shows a state in which the small force trip device is reset. 1, FIG. 2, FIG. 3, and FIG. 4, 51 is a movable iron core, 52 is a fixed iron core, 53 is a closing coil, and 54 is a link connecting the movable iron core 51 and the lever 55. The link 84 connects the lever 55 and the lever 80. The lever 55 is rotatable around a shaft 73, and 58, 59, 90, 85, 86 and 87 are shafts connecting these parts. 75 is a small force trip device according to the present invention. 81 is a reset lever, 82 is a link connecting the 80 lever and the 81 reset lever, 89 is the rotation center axis of the reset lever 81, 100 is a roller attached to the tip of the reset lever 81, 31 is a permanent magnet, and 32 is Fixed iron cores attached to both sides of the permanent magnet, 33 a movable iron core, 34 a trip rod screwed to the movable iron core 33, 36 an open spring, 37 a coil, and 38 a case. Reference numeral 101 is a bearing through which the trip rod 34 penetrates, and 102 is a column (round bar) which serves as a guide when the open spring 36 and the movable iron core 33 move up and down.

Next, the operation of the small force trip device of the present invention will be described. 2, the closing coil of the circuit breaker
When a current is supplied from a power source separately prepared for 53, the movable iron core is attracted to the fixed iron core, and the lever 55 connected by the link 54 rotates clockwise around the shaft 73. This movement is transmitted to the lever 80 by the link 84, the lever 80 rotates counterclockwise about the shaft 83, and further transmitted to the link 82. In FIG. 1, the attraction force of the permanent magnet is temporarily weakened by a signal (current) sent to the coil 37 from a separately prepared control device, and the movable iron core 33 is fixed together with the trip rod 34 by the force of the compression coil spring 36. It is in a state of being pushed upwards away from 32. The 82 link transmitted from the closing operation of the circuit breaker rotates the 81 reset lever counterclockwise about the 89 axis, and the roller 100 at the tip pushes down the movable core of 33 and compresses the open spring 36. At the same time, the movable iron core 33 is gradually moved downward, and the permanent magnet 31 attracts the movable iron core to the fixed iron core 32, and the state shown in FIG. 3 is entered. The guide when the movable iron core moves downward is the column 102.
And 101 bearings. In FIG. 4, the reset lever 81 returns to its original position due to the interruption of the current supplied from the separately prepared power supply to the closing coil 53 of the circuit breaker, but the movable iron core 33 is fixed by the permanent magnet 31.
Adsorbed and held by 32 and reset is completed.

Embodiment 2. In the above embodiment, the reset operation is performed during the closing operation, but the same effect can be expected even during the tripping operation by appropriately selecting the compression coil spring force.

Embodiment 3. Further, the movable iron core 33 is of a system in which it is attracted and fixed by a permanent magnet, but another mechanical system may be used.

[0012]

As described above, since the reset mechanism performs the rotational movement as described above, the reset is performed with a constant stroke without any change with the passage of time, and the two iron rollers uniformly reset the left and right sides of the movable iron core. The reset operation can be stabilized.

[Brief description of drawings]

FIG. 1 is a sectional view showing an operating state of a small force trip device according to the present invention.

FIG. 2 is a sectional view showing the entire reset mechanism of the small force trip device according to the present invention.

FIG. 3 is a cross-sectional view showing the middle of the resetting process of the small force trip device according to the present invention.

FIG. 4 is a cross-sectional view showing a state in which the reset operation of the small-force trip device according to the present invention has been completed and the roller has returned to its original position.

FIG. 5 is a sectional view of a conventional small force trip device in a reset state.

FIG. 6 shows a state in which only the upper part of FIG. 5 is extracted, but the device is operated and the lever is rotated counterclockwise.

FIG. 7 is a structural side view of a reset mechanism portion of a conventional device.

FIG. 8 is a structural diagram cross section of a circuit breaker to which a conventional device is attached, showing a circuit breaker closed state.

FIG. 9 shows a circuit breaker tripped state in a sectional view of the structure of a circuit breaker to which a conventional device is attached.

[Explanation of symbols]

 31 Permanent magnet 32 Fixed iron core 33 Movable iron core 34 Trip rod 36 Compression coil spring 37 Coil 81 Reset lever 100 Roller 102 Strut

Claims (1)

[Claims] 1. A small force trip device reset mechanism, characterized in that a roller is provided at a tip of a reset lever of a small force trip device of a circuit breaker to carry out a reset operation by rotating the roller.