JP3097300B2 - Movable contact device for circuit breakers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movable contact device in a circuit breaker such as a wiring circuit breaker or an earth leakage circuit breaker, and more particularly to sliding a movable contact that is opened and closed and a connection conductor fixed to a case. The present invention relates to a movable contact device electrically connected by dynamic contact.

[0002]

2. Description of the Related Art FIGS. 7 to 9 show a conventional movable contact device of this type. FIG. 7 is a longitudinal sectional view, and FIG. 8 is a diagram showing a movable contact device and a connecting conductor shown in FIG. FIG. 9 is a plan view in which a part of FIG. 8 is cut away. First, in FIGS. 8 and 9, reference numeral 1 denotes a movable contact made of a plate-like conductor, and a movable contact 1 a is joined to a distal end portion. 2
Is a connecting conductor bent from a plate body, and a pair of arms 2b is raised on both sides of a flat mounting portion 2a.
The upper end of the arm 2b elastically sandwiches the base end of the movable contact 1 so as to make sliding contact with both side surfaces thereof. A fulcrum pin 3 is inserted into a through hole (not shown) of the sliding contact portion, and the movable contact 1 is rotatably supported by the fulcrum pin 3.

[0003] Reference numeral 4 denotes a mounting bracket formed of a metal plate in a gate shape. As shown in FIG.
Are connected to the left and right side walls by caulking. At this time, a contact spring 5 made of a compression spring is fitted into a portion of the fulcrum pin 3 protruding on both sides of the connection conductor 2, and the connection conductor 2 is compressed between the contact spring 5 and the mounting bracket 4.
To press the movable contact 1. A tongue-shaped engaging piece 4a is formed on the left and right side walls and the upper wall of the mounting bracket 4 by being cut outward and bent.

[0006] Reference numeral 6 denotes a current limiting latch for performing current limiting interruption.
Both arms are bent and formed in a bifurcated manner so as to sandwich the movable contact 1, and are rotatably supported by the mounting bracket 4 by pins 7 near the bent portion. On the other hand, a current limiting pin 8 is attached to the movable contact 1 so that both ends protrude left and right, and both ends face the current limiting latch 6. A pair of right and left current limiting springs 9 composed of tension springs are mounted between the upper end of the current limiting latch 6 and the top of the mounting bracket 4, and the current limiting latch 6 receives a clockwise force around the pin 7. One of the inclined surfaces 6 a of the rear surface formed in a mountain shape is pressed by the current limiting pin 8. The current limiting spring 9 also serves as a contact spring for the movable contact 1, and the movable contact 1 is counterclockwise about the fulcrum pin 3 as a fulcrum by the force of the current limiting spring 9 acting on the current limiting pin 8 from the current limiting latch 6. Is pressed by the fixed contact 10 (FIG. 7).

The movable contact 1 and the connecting conductor 2 integrated as shown in FIGS. 8 and 9 are held in a holder 11 made of molded resin as shown in FIG. Holder 11
Has a hollow structure in which left and right side plates are connected to each other up and down, and the movable contact 1 and the connection conductor 2 pushed into the hollow from the back thereof are formed by the engagement piece 4 a of the mounting bracket 4 and the holder 11. Is fixed to the holder 11 by elastically engaging with a step provided on the inner wall surface of the holder. The holders 11 of the respective poles holding the movable contact 1 are connected to each other by an opening / closing shaft (not shown) integrally formed, and a toggle link 13 connected by a pin 12 by an opening / closing mechanism (not shown) connected to the holder 11 of the center pole. , And the respective electrodes are simultaneously opened and closed. The connection conductor 2 is fixed to a case (not shown) by a screw at an attachment portion 2 a, and the movable contact 1 and the connection conductor 2 slide with each other around the fulcrum pin 3 with the opening and closing operation.

In the closed state shown in FIG. 7, when a large current such as a short-circuit current passes through the circuit breaker, the conductors of the movable contact 1 and the fixed contact 10 flow in opposite directions as indicated by arrows. The movable contact 1 is driven clockwise in the drawing by the electromagnetic repulsion generated between the currents. At this time, when the movable contact 1 is slightly rotated, the surface of the current limiting latch 6 with which the current limiting pin 8 comes into contact changes from one inclined surface 6a to the other inclined surface 6a.
Then, the direction of the force of the current limiting spring 9 to the movable contact 1 is reversed from the counterclockwise direction to the clockwise direction. As a result, the movable contact 1 is connected to the electromagnetic repulsive force and the current limiting spring 9.
Is further driven in the opening direction by both of the spring forces of (1) and (2) to perform the current limiting interruption.

[0007]

In the above conventional configuration, the fulcrum pin 3 for supporting the movable contact 1 is fixed to the holder 11 via the mounting bracket 4. However, in such a configuration, since the fulcrum pin 3 is crimped to the mounting bracket 4, the work is troublesome, and the mounting bracket 4 is connected to the engaging piece 4.
a is engaged with and fixed to the step of the holder 11, so that
The dimensional control of the amount of engagement between the two was troublesome. Therefore, an object of the present invention is to provide a movable contact device of a circuit breaker that has a simple configuration and is easy to assemble.

[0008]

In order to achieve the above object, according to the present invention, both ends of a fulcrum pin inserted into a sliding contact portion between a movable contact and a connecting conductor are supported by bearing plates, and these are supported by bearing plates. The bearing plate is pressed against the recess on the inner wall surface of the holder by a contact spring and fixed. In the above configuration, if the flange surrounding the bearing hole is integrally formed on the contact spring side of the bearing plate, the length of the fulcrum pin can be shortened and the assembly is further facilitated.

[0009]

In the present invention, both ends of the fulcrum pin are supported by the bearing plate without the mounting bracket, and the bearing plate is pressed and fixed to the recess on the inner wall surface of the holder using the force of the contact spring. The bearing plate may be a simple washer-shaped plate material as compared with a conventional mounting bracket, so that the configuration is simple, and the fulcrum pin does not need to be caulked, thereby facilitating the assembling work. If a flange is formed on the bearing plate by burring, etc., the length of the fulcrum pin can be shortened by the thickness of the bearing plate,
It becomes easy to insert a movable contact or the like into the holder.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 is a longitudinal sectional view of the movable contact device, FIG. 2 is a sectional view taken along the line II-II, FIG. 3 is a rear view of FIG. 1, and FIG. 4 (A) is a front view of the bearing plate in FIG. FIG. 5B is a side view, FIG. 5A is a front view showing another embodiment of the bearing plate, FIG. 5B is a side view thereof, and FIG. 6 is provided with the movable contact device of FIG. It is a principal part longitudinal cross-sectional view of the circuit breaker which was made. Note that the same reference numerals are used for the portions corresponding to the conventional example.

1 to 3, the structures of the movable contact 1 and the connecting conductor 2 are substantially the same as those of the conventional example, and the base end of the movable contact 1 is slid with the arm 2b of the connecting conductor 2 therebetween. Contact springs 5 composed of compression springs are fitted into both ends of the fulcrum pin 3 which is in dynamic contact and passes through the sliding contact portion. However, in this case, there is no conventional mounting bracket 4 and the fulcrum pin 3
Are supported by round washer-shaped bearing plates 14 shown in FIG. Reference numeral 15 denotes a bearing hole for receiving the fulcrum pin 3.

On the other hand, as shown in FIGS. 1 and 2, a groove-shaped recess 16 into which a bearing plate 14 is fitted is formed on the inner wall surfaces of the left and right side walls of the holder 11 along the front-rear direction (the left-right direction in FIG. 1). A groove 17 that escapes the tip of the fulcrum pin 3 is formed.
The recess 16 and the groove 17 concentrically overlap each other at a predetermined position of the fulcrum pin 3 in the drawing, and the groove 17 is open to the rear of the holder 11. The recess 16 may have a circular shape following the contour of the bearing plate 14, but is opened in a groove shape toward the front of the holder 11 for molding reasons. The groove 17 is deeper than the recess 16.

Reference numeral 6 denotes a current-limiting latch which operates in the same manner as in the prior art. In this case, a square-shaped piece 6c located on both sides of the movable contact 1 and a pair of left and right arms 6d below the same are integrally formed of a plate material. The holder 1 through the pin 7 inserted into the arm 7d.
1 rotatably supported. A current limiting spring 9 composed of a compression spring is inserted between the current limiting latch 6 and the holder 11, and the current limiting latch 6 receives a counterclockwise force shown in FIG. The surface 6 a is pressed against both ends of the current limiting pin 8 fixed to the movable contact 1.

To assemble the movable contact device in the state shown in the figure, the movable contact 1 and the connection conductor 2 are connected by fulcrum pins 3, contact springs 5 are fitted at both ends thereof, and a bearing plate 14 is further fitted thereon. The inserted member is inserted from the back into the holder 11 in which the current limiting latch 6 and the current limiting spring 9 have been previously assembled. At this time, the left and right ends of the fulcrum pin 3 enter the groove 17, and the bearing plate 14 slides on the inner wall surface of the holder 11 while compressing the contact spring 5. This bearing plate 14
When it reaches the recess 16, it falls into the recess by the force of the contact spring 5 and is pressed against the bottom surface of the recess 16. In this state, the current limiting pin 8 comes into contact with the inclined surface 6a of the current limiting latch 6, the current limiting spring 9 is in a compressed state, and the bearing plate 14 is pressed against the end face of the concave portion 16 by the reaction force to be positioned in the illustrated state. You. The fulcrum pin 3 is positioned in the axial direction with both end surfaces in contact with the bottom surface of the groove 17.

A flange 14a is formed on the bearing plate 14 of FIG. 5 by burring so as to surround the bearing hole 15. If the flange 14a is inserted into the inside of the contact spring 5 by using such a bearing plate 14, even if the length of the fulcrum pin 3 is shortened by the thickness of the bearing plate 14, the movable contact 1 There is no problem in fitting the bearing plate 14 into the end of the fulcrum pin 3 before inserting the support pin 3 into the holder 11, and in that case, the bottom surfaces of the concave portion 16 and the groove 17 can be aligned on the same plane. As a result, insertion of the movable contact 1 and the like into the holder 11 is facilitated, and the configuration of a mold for molding the holder 11 is simplified. In the illustrated embodiment, the bearing plate 14 is circular, but may be square, such as square. In that case, the shape of the recess 16 is also adjusted to that.

FIG. 6 shows a circuit breaker provided with the above-mentioned movable contact device. The current is supplied from the fixed contact 10 integrated with the power supply terminal to the movable contact 1, the connection conductor 2, the overcurrent trip device 18 and the like. Flows through the conductor 19 integrated with the load side terminal.
When the operation handle 20 is tilted rightward in the drawing from the illustrated closed state, the opening / closing mechanism 21 operates, the holder 11 connected to the toggle link 13 rotates clockwise, and the movable contact 1 is separated.

When the current is in an overcurrent state, the opening / closing mechanism 21 is actuated by the action of the overcurrent trip device 18, and
The movable contact 1 is separated. In this case, when a large current such as a short-circuit current flows, the movable contact 1 is driven by the above-described electromagnetic repulsion, and the current limiting pin 8 contacts the inclined surface 6b of the current limiting latch 6 (FIG. 1). . As a result, the movable contact 1
Receives a clockwise force from the current limiting spring 9 with the fulcrum pin 3 as a fulcrum, and is quickly opened before the holder 11 rotates.

According to the illustrated embodiment described above, both ends of the fulcrum pin 3 are supported by the bearing plate 14 pressed and fixed to the recess 16 by the contact spring 5, and the fulcrum pin 3 is positioned in the axial direction by the holder 11. With this configuration, the caulking of the fulcrum pin 3 becomes unnecessary, and the management of the amount of engagement between the engaging piece 4a of the mounting bracket 4 (FIG. 8) and the holder step is eliminated. The bearing plate 14 is provided with the mounting bracket 4.
Since the configuration is simpler than that of, it is easy to manufacture.

[0019]

According to the present invention, both ends of the fulcrum pin inserted into the sliding contact portion between the movable contact and the connection conductor are supported by the bearing plate pressed and fixed in the recess on the inner wall surface of the holder by the contact spring. This eliminates the need for caulking the fulcrum pins and cumbersome dimensional control of the mounting bracket, thereby reducing the number of assembling steps and simplifying the component configuration, thereby reducing costs.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II of FIG.

FIG. 3 is a rear view of FIG. 1;

4 shows a bearing plate in FIG. 2, (A) is a front view,
(B) is a side view.

5 shows different embodiments of the bearing plate, FIG. 5 (A) being a front view and FIG. 5 (B) being a side view.

FIG. 6 is a vertical sectional view of a main part of a circuit breaker provided with the movable contact device of FIG. 1;

FIG. 7 is a longitudinal sectional view of a conventional example.

8 is a diagram showing a state before the movable contact and the connection conductor in FIG. 7 are mounted on a holder.

FIG. 9 is a plan view in which a part of FIG. 8 is broken.

[Explanation of symbols]

 Reference Signs List 1 movable contact 2 connection conductor 3 fulcrum pin 5 contact spring 11 holder 14 bearing plate 16 recess

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-19938 (JP, A) JP-A 62-12238 (JP, U) JP-B-51-6870 (JP, B2) (58) Field (Int.Cl. ⁷ , DB name) H01H 73/02

Claims (2)

(57) [Claims] 1. A fulcrum pin which is in sliding contact with a connecting conductor fixed to a case on both side surfaces of a movable contact made of a plate-like conductor held by an insulator holder, and which is inserted into the sliding contact portion. A movable contact device of a circuit breaker in which a contact spring composed of a compression spring for pressing the connection conductor against the movable contact is fitted into portions projecting from both sides of the connection conductor. A movable contactor device for a circuit breaker, characterized in that the bearing plates are supported and pressed by a contact spring against a recess on the inner wall surface of the holder. 2. The movable contact of a circuit breaker according to claim 1, wherein a flange surrounding the bearing hole is integrally formed on the contact spring side of the bearing plate.