JPS5942937B2 - Breaker opening mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a breaker opening mechanism that instantaneously performs forced tripping when a large current flows such as during a short circuit.

When a current several times higher than the rated value, such as a short-circuit current, flows, the current is limited by instantaneous interruption by forced tripping using a solenoid without waiting for the node of the trip link that maintains the closed state to collapse. A current-limiting type breaker maintains its effectiveness.

However, even in this case, the contact cannot be removed without unlatching the trip link, so the solenoid first drives the tripping fitting to unlatch the trip link, and then forcibly removes the contact. It is designed to be pulled out.

This forced tripping of the contact simultaneously drives the latch link that latched the trip link via the trip link.

Therefore, the solenoid must not only move the contact, but also move the launch link via the trip link.

The force required to drive the latch link through the trip link acts as a drag force for the tripping action, which slows down the rise in the opening speed of the contact and causes an arc to occur between the contacts. The sticking time becomes longer and the short circuit breaking performance deteriorates.

The present invention has been devised in view of these points, and provides a breaker opening mechanism that reduces such resistance during forced tripping in the event of a short circuit, thereby improving the opening speed. The purpose is to

To explain the present invention below, the present invention includes a solenoid consisting of a coil through which a load current is passed and a movable iron core driven by the magnetomotive force of the coil, and a bimetal that is heated and bent by the load current as a tripping device. At the same time, the hanging piece is rotatably supported by the frame, is biased in one direction by a return spring, and is driven by a movable pin that interlocks with the movable iron core of the solenoid of the tripping device, or is driven by a bimetal to return. A tripping metal fitting that rotates against the bias of a spring; a latch link rotatably supported on the frame and having an engaging portion that engages with a retaining protrusion of the tripping metal fitting; and a latch link provided on the frame. a contactor which is rotatably supported with a long groove that engages with the pivot shaft of the solenoid and which is connected to a head at one end of the movable iron core of the solenoid; and a vertically elongated hole provided in the latch link. A link in which a movable shaft at one end is inserted into a horizontally long hole provided in the frame, and one end is rotatably connected to the other end of this link, and a movable contact is provided to connect the connecting shaft at the other end. A trip link with a toggle link structure, which is composed of a link connected to a child, and a link whose one end is connected to the connecting point of both links and whose other end is connected to a link that rotates together with the handle; and a spring means for biasing the trip link in the trip direction, and the engagement of the tripping fitting and the latch link maintains the closed state of the contact by the trip link against the bias of the spring means. In the tripping device, the tripping fitting that is driven by the tripping device to release the engagement between the retaining portion of the latch link and the engagement protrusion is provided with a pressing protrusion that drives the latch link in the direction of the tripping operation of the trip link. When the movable iron core of the solenoid forcibly trips the contact, the input from the tripping fitting also forcibly moves the latch link, making it easy for the trip link to lose its equilibrium state. This is how it was done.

The following will be described in detail based on illustrated embodiments.

In the figure, 1 is a solenoid that performs forced tripping, and includes a coil 21 through which a load current is passed, a coil tube 22 that holds this coil 21 on the outer peripheral surface, and a movable iron core slidably arranged inside the coil tube 22. 23, it is composed of a movable pin 24 that is coaxial and in line with the movable iron core 23, a fixed iron core 25, and a return spring 26, and one end of the movable pin 24 is connected to the suspension of the tripping fitting 11 that is pivotally supported on the frame 3. A head 28 is provided which faces the piece 41 with a small distance therebetween, and one end of the movable iron core 23 penetrates an engagement hole 27 provided at the lower part of the contactor 4 and engages with the retention hole 27 .

Reference numeral 6 denotes a bimetal as an overcurrent sensor, and a series of bimetals are fixed to the frame 3, and the free end located below the horizontal piece 42 of the tripping fitting 11 is displaced upward when the temperature rises, and the tripping fitting 11 is moved upward. It is designed to rotate against the return spring 31.

Reference numeral 12 designates a latch link provided with a locking hole 33 into which an engaging protrusion 32 provided on the tripping metal fitting 11 is locked;
There is a vertical hole 34 approximately directly below this pivot point.
A movable shaft 17 attached to one end of the link 13 engages with this vertically elongated hole 34 and a horizontally elongated hole 35 provided in the frame 3.

At the other end of this link 13 are two other links 14 and 15.
These links 13, 1 are rotatably connected at one end of each
4, 15 and the latch link 12 constitute a trip link, and the other end of the link 14 is pivotally supported by the connecting shaft 18 to approximately the middle of the contactor 4, and the other end of the link 15 is pivotally supported by the frame 3. They are each rotatably connected to a link 16 that rotates integrally with the operating handle 10.

The contact 4, which has a movable contact 29 at its lower end, an engagement hole 27 above it, and a connecting shaft 18 at its center, has a long groove 30 at its upper end that engages with a pivot shaft 19 fixed to the frame 3. The spring pressure of the return spring 5 is applied to the portion between the connecting shaft 18 and the pivot shaft 19.

In the figure, 36 is a return spring of the operating handle 10, 37 is an arc travel plate extending from the frame 10, and 38 is an arc extinguishing block placed in the arc extinguishing chamber 7. The load current is transmitted from the fixed contact 39 to the movable contact 29, It flows to the contactor 4, the braided copper wire 40, the bimetal 6, and the coil 21.

1 and 2a show the on state, in which the trip fitting 11 and the launch link 12 engage, and the contact 4 is pressed to the right in the figure by the trip link, compressing the return spring 5. At the same time, the movable contact 29 is brought into contact with the fixed contact 39.

Further, the contact pressure is maintained by the rotational moment applied from the return spring 5 about the connecting shaft 18.

In other words, the return spring 5 also serves as a contact pressure spring.

When the operating handle 10 is tilted to the left, the link 15 is lifted up, and the contact 4 is also moved to the left to open the contact.

This state is shown in Figure 2.

If an overcurrent flows in the on state, the bimetal 6 is displaced upward due to its own heat generation, and the tripping fitting 1
1 is rotated against the return spring 31.

As a result, as shown in FIG.
The movable contact 29 of the contactor 4 is removed from the fixed contact 39 by tripping the trip link.

When a current several times higher than the rated value flows, such as a short-circuit current, the solenoid 1 is activated to perform forced tripping. However, when the movable iron core 23 is attracted and driven, the head 28
Before pulling, the movable pin 24 pushed by the movable iron core 23 first kicks the hanging piece 41 and rotates the tripping fitting 11.

At the beginning of this rotation of the tripping metal fitting 11, the engagement protrusion 32 is disengaged from the engagement hole 33 of the latch link 12, and then the pressing protrusion 8 provided adjacent to the engagement protrusion 32 is used to remove the latch link 12 from the engagement protrusion 32. The latch link 12 is forcibly rotated by pushing the tip of the latch link 12, thereby shifting the trip link to the trip state.

Further, the head 28 of the movable iron core 23 pulls the contactor 4 and enters a forced tripping operation shortly after the moment when the engagement protrusion 32 and the latch link 12 are disengaged.

Since the latch link 12 that keeps the trip link latched at the same time as this tripping is driven by the pressing protrusion 8, there is no need to move the latch link 12 via the trip link at the beginning of forced tripping. , latch link 1
This means that the drag at the beginning of the second movement can be reduced.

When the opening operation progresses halfway in this way, the trip is completed with the addition of drive by the return spring 5.

In this way, in the present invention, when forced tripping occurs, the latch of the trip link is released almost directly via the tripping fitting, without using the trip link, which is an element with a large transmission delay, and the trip link is brought into the trip state. In order to make the transition, it is possible to reduce the drag force at the beginning of the movement of the latch link and improve the rise of the opening speed.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2a is a cross-sectional view of an embodiment of the present invention. b, ctd are explanatory diagrams of the same operation as above, FIG. 3 is an exploded perspective view of the same, and FIG. 4 is a front view of the main parts of the same. tripping metal fittings,
12 is a latch link, 21 is a coil, 23 is a movable iron core,
32 indicates an engaging protrusion.

Claims (1)

[Claims] 1 A solenoid consisting of a coil through which a load current is passed and a movable iron core driven by the magnetomotive force of the coil, and a bimetal that is heated and bent by the load current are equipped with a tripping device, and a frame is rotated. The hanging piece is freely supported and biased in one direction by a return spring, and is driven by a movable pin that interlocks with the movable iron core of the solenoid of the tripping device. a latch link rotatably supported by the frame and having an engaging portion that engages with an engaging protrusion of the tripping metal; and a pivot shaft provided on the frame. a contactor having an engaging long groove and rotatably supported and connected to the head at one end of the movable iron core of the solenoid; a vertically elongated hole provided in the latch link; and a laterally elongated hole provided in the frame. A link having a movable shaft at one end inserted through the hole, and a link having one end rotatably connected to the other end of this link, and the connecting shaft at the other end being connected to a contact provided with a movable contact. A trip link with a toggle link structure, which has one end connected to the connecting point of both links and a link whose other end is connected to a link that rotates together with the handle, and a trip link that rotates in the trip direction. and a spring means for biasing, the closed state of the contact by the trip link is maintained against the bias of the spring means by engagement with a latch link with a tripping metal fitting, The tripping fitting that is driven by the release device to release the engagement between the engaging portion of the latch link and the retaining protrusion is equipped with a pressing protrusion that drives the latch link in the direction of the tripping operation of the trip link. The opening mechanism of the breaker.