JPS60105133A - Movable contactor unit of circuit breaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a movable contact device for a circuit breaker.

[Background technology]

If the fixed contact and the movable contact contact each other unevenly due to dimensional errors, or even if they are in precise contact, if the contact wears out unevenly due to repeated separation or arcing during short circuit breakage, the contact reliability of the contact will deteriorate. However, there were drawbacks such as unstable contact resistance and abnormal temperature rise. This is a particularly important problem for circuit breakers with high cutoff characteristics.

[Purpose of the invention]

Therefore, an object of the present invention is to provide a movable contact device for a circuit breaker that can stabilize the contact resistance of the contacts and improve the contact reliability. : To provide.

[Disclosure of the invention]

This invention is characterized in that the shaft hole of the shaft support of the movable contact is made larger than the shaft, so that the width direction of the movable contact can be freely tilted within a predetermined range. Even if the fixed contact and the movable contact contact or wear out on one side, the movable contact is tilted by the amount of clearance between the shaft and the shaft hole, so that complete contact can be achieved.

A circuit breaker to which an embodiment of the present invention is applied is shown in FIGS. 1 to 4. In other words, 1fdi! 3 units, 2Ir
It is an i-cover, and these make up the main body of the book. 3 is the power supply side terminal, 4 is the load 1llllI terminal, 5
1 is a contact portion, 6 is an arc extinguishing device, 7 is an overcurrent operating element, 8 is a movable contact with a reversing mechanism, 9 is a handle, and 10 is an opening/closing/trip link mechanism.

In the contact part 5, 11 is a fixed contact connected to the power supply side terminal 3, 12 is a fixed contact, 13 is an arc drive coil connected to the tip of the fixed contact 11, 14 is an arc fixed contact, and 15 is a fixed contact. The arc travel plate 17 is connected to the grid 16 of the arc extinguisher, and 17 is an arc drive yoke. Also, 1
8 is a movable contact provided at the end of the movable contact 8;
The movable contact 8 is provided with abutments 19 on both sides, and a bearing plate 20 that also serves as a stopper and extends from the abutment 19 is overlapped at the center of the base end of the movable contact 8. A shaft hole 21 is formed in the shaft hole 21 . Also, the movable contact 8
A notch 23 in the bearing plate 22 of the stopper 19 extending from the tip of the
A shaft 24 is provided on the shaft 24, an arc contactor 25 is pivotally supported on the shaft 24, and a contact pressure spring (not shown) is interposed. In this movable contactor 8 , a shaft 26 having an outer diameter a predetermined smaller than that of the shaft hole 21 is passed through the shaft hole 21 , and this shaft 26 is mounted on a contactor holding arm 27 . In addition, the shaft 26 of the movable contact 8
The base end of the armature 280 is pivotally supported, and its free end extends to the opposite side of the movable contact 8, and a spring receiving plate 30, 31 is provided between the shaft 29 provided at the free end and the shaft 24. A contact pressure/reversal barb 32 is tension-suspended via the contact pressure/reversal barb 32. The arm 27 is supported on the instrument stand 1 by a shaft 33, and is connected and supported by the link 34 of the link mechanism IO. 35 is a braided wire that electrically connects the arc contactor 23 and the movable contactor 8; 36 is a braided wire that electrically connects the movable contactor 8 and the load side terminal 4 side.

Figure 1 shows the on state, with power supply side terminal 3 and load side terminal 4.
Main fixed contact 11. Fixed contact 12° Movable contact 1
8. Movable contactor 81 braided wire 36. Electricity is applied to the electric path constituted by the overcurrent operation element 7. Note that when the movable contact 8 is turned on, the arc movable contact 23 of the arc contact 23
a contacts the arc fixed contact 14 first, and then the movable contact 18 contacts the fixed contact 12.

The off state is when the handle 9 is tilted to the right (clockwise) in FIG. At this time, the center line of the tension spring 37 of the link mechanism 10 crosses the tripping plate connecting shaft 38 to the right, and the link connecting shaft 39 is pulled upward and the arm 2
7 is the turn! IJb, the movable contact 8 performs an opening operation.

A trip state occurs when an overcurrent flows through the electrical circuit. In this case, the armature 28 is attracted to the magnetic arm 27 by the magnetic flux created by the braided wire 36, and when the reversing spring 32 which also serves as contact pressure crosses the shaft 26, the movable contact 8 is reversed and opened.

At the same time, the overcurrent operation element 7 operates to operate the launch fitting 40, and the trip plate 41 is released, causing the link mechanism 1o to become unbalanced.

As a result, the arm 27 rotates via the link 42.34, the movable contact 8 further moves in the opening direction, and the handle 9
becomes neutral and becomes tripped.

Along with these opening operations, the movable contact 18 becomes the fixed contact 1.
2 also separates first, and then the arc movable contact 23a separates from the arc fixed contact 14. Therefore, the short circuit current at the R1 pole flows through the arc movable contact 23a, and the main arc is generated between the arc movable contact 23a and the arc fixed contact 14, and the arc is driven by the yoke 17 toward the grid 11 side by the magnetic field of the arc drive coil 13. and grid 11
The arc is cooled and extinguished. Note that a slight arc is generated when the movable contact 18 is opened, but this is also driven toward the grid 11 by the magnetic field generated by the yoke 17.

By the way, if the contact surfaces of the movable contact 18 and the fixed contact 12 are not parallel due to dimensional errors or the like, or if one-sided wear 9 occurs in the contacts 18 and 12, in either case, the ON state will be as shown in FIGS. As shown in FIG. 4, the gap due to the difference in size between the shaft 26 and the shaft hole 21 is absorbed, and the movable contact 18 is tilted in the width direction and the longitudinal direction so as to be in complete contact with the fixed contact 12. Therefore, the contact f3 reliability of the contacts 12 and 18 can be improved by preventing uneven wear as in the conventional case.

Note that the movable contact of the present invention is not limited to the above-mentioned inversion (one size or so), and can be applied.

〔Effect of the invention〕

As described above, the movable contact device for a circuit breaker of the present invention has the effect that contact reliability can be improved even if uneven contact or uneven contact occurs.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a circuit breaker to which an embodiment of the present invention is applied, Fig. 2 is an exploded perspective view of a movable contact device, and Figs. 3 and 4 are front views of contacts in the on state. It is. 8. Movable contact, 12. Fixed contact, 18. Movable contact, 21. Shaft hole, 26. Shaft.

Claims (1)

[Claims] It includes a fixed contact, a movable contact having a movable contact at its tip that separates from the fixed contact, and a shaft support that pivotally supports the base end of the movable contact. A movable contact device for a circuit breaker, characterized in that the width of the movable contact is increased and the width direction of the movable contact is freely inclined within a predetermined range.