JPH04212233A - Mounting device of switching mechanism supporting frame in circuit breaker - Google Patents

Abstract

PURPOSE:To simplify mounting of a frame for supporting a switching mechanism on a case and stiffen its fixing. CONSTITUTION:Tongue-shaped mounting pieces 32 are formed on both side plates 29 of a supporting frame 28 by cut-bending them in a shape of a reversed trapezoid and these mounting pieces 32 are made to bite into the stepped parts 39 of a case partition 1a so as to be fixed in the vertical direction. Further, a latch pin 14 for making a supporting frame 28 to support a latch 15 is fitted into grooves 41 of a case partition 1a so as to be fixed in the longitudinal direction. The supporting frame 28 can be simply fixed only by being pushed into a case 1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for attaching a support frame of an opening/closing mechanism to a case of a small-sized circuit breaker such as a molded circuit breaker.

0002

2. Description of the Related Art FIG. 7 is a longitudinal sectional view of a conventional circuit breaker (mold circuit breaker). In FIG. 7, 1 is an insulating case, 2 is a cover, and the case 1 includes a fixed contact 3 that also serves as a terminal on the power supply side, a movable contact 4 that moves toward and away from the fixed contact 3, and an electromagnetic attraction. The disconnecting device 5, the lead wire 6 connecting the movable contact 4 and one end of the trip coil of the electromagnetic tripping device 5, and the load side terminal 7 connected to the other end of the trip coil of the electromagnetic tripping device 5 are stored, A current-carrying path is formed by these.

The movable contact 4 is rotatably supported by a holder 9 by a shaft 8, and is constantly urged toward the fixed contact 3 by a contact spring 10 made of a torsion spring. Further, each pole of the holder 9 is connected by an insulating opening/closing shaft 11, and is rotatably supported by the case 1 via the shaft end of the opening/closing shaft 11. 12 is a support frame for supporting the opening/closing mechanism 13 that opens and closes the movable contact 4, and has side plates that stand upright on the left and right with the movable contact 4 sandwiched therebetween;
It is attached to the case 1 with screws 27. Opening/closing mechanism 1
3 is a latch 15 rotatably supported on the support frame 12 via a latch pin 14, a toggle link 16 connected at both ends to the latch 15 and the holder 9, respectively, an operation handle 17a on the head, and a support frame at the tip. A bifurcated handle lever 17 is swingably supported by the handle lever 12, and an opening/closing spring 19 is stretched between the central connecting pin 18 of the toggle link 16 and the head of the handle lever 17.
It is composed of etc.

The tip of the latch 15 (right end in the figure) is connected to the pin 2.
The latch receiver 21 is always engaged with the pin 21a of the latch receiver 21 which is rotatably supported by the support frame 12 via the pin 21a, and is prevented from rotating in the counterclockwise direction. Further, the latch receiver 21 engages with a claw 23 rotatably supported by the support frame 12 via a pin 22, and is prevented from rotating clockwise in the figure. An insulating cross bar 24 extending left and right is attached to the claw 23 so as to face the armature 25 of the electromagnetic tripping device 5. In addition, 26 is an arc extinguishing device, which is attached to the case 1 so as to surround the movement locus of the movable contact 4.

In such a circuit breaker, when the operating handle 17a is turned off in the right direction from the closed state shown in the figure, the opening/closing spring 19 moves from the left side of the toggle link 16 to the right side in the figure. The spring force exceeds the dead center, and the toggle link 16 reverses to open the movable contact 4. Furthermore, when a large current such as a short-circuit current flows through the circuit, the armature 25 of the electromagnetic tripping device 5 is attracted and rotates clockwise in the figure, causing the crossbar 2
4 to rotate the claw 23 counterclockwise. Therefore,
The claw 23 and the latch receiver 21 are disengaged, and the latch receiver 21
is flipped up by the force from the latch 15 applied to the pin 21a and rotated clockwise in the figure. As a result, pin 21
a is also disengaged from the latch 15, and the latch 15 rotates counterclockwise in the figure. Therefore, the toggle link 16 moves the opening/closing spring 19 from the right side to the left side in the figure, and in the process, when the spring force on the toggle link 16 exceeds the dead center, the toggle link 16 is reversed and the movable contact 4 This will cause them to separate.

[0006]

In such a conventional circuit breaker, the support frame 12 of the opening/closing mechanism is fastened to the case 1 with screws 27, as shown in FIG. Here, (A) of FIG. 8 is a plan view of the case to which the support frame is attached, and (B) is a side view of the case, partially taken in cross section along line BB in (A). That is, in FIG. 8, 1a is a partition wall that divides the case 1 into each pole, but the support frame 12 has a partition wall 1a at the center pole.
It is placed on the mounting seats 1b and 1c which are built up along the
It is fixed with three screws 27 screwed in from the back side of the case 1.

However, the mounting seat 1b built up on the case 1 for screw tightening bulges out from the partition wall 1a, narrowing the space in which the opening/closing mechanism and the movable contact 4 can move, and placing restrictions on the shapes of these parts. This makes design work difficult. Also,
There is also the problem that screw tightening work is time-consuming and assembly work is troublesome. Therefore, this invention fixes the support frame to the case without using screws, thereby expanding the movable space inside the case and increasing the degree of freedom in the shape of parts. It is an object of the present invention to provide a support frame mounting device for a mechanism.

[0008]

[Means for Solving the Problems] The present invention involves bending a portion of the left and right side plates of the support frame of the opening/closing mechanism outward in a tongue shape to form an inverted V-shaped mounting piece, and attaching the case partition wall. A step portion that engages the mounting piece of the support frame inserted into the case from above, and a groove that engages both ends of a latch pin that supports the latch of the opening/closing mechanism on the side plate, on a surface facing the side plate. The above object is achieved by providing a support frame and fixing the support frame to the case. By forming a positioning piece projecting obliquely forward at the end of the side plate of the support frame, and providing a pressing portion for pressing the positioning piece against the surface of the case partition facing the side plate, the support frame can be fixed. can be made even stronger. Furthermore, if the width of the groove in the case partition wall into which both ends of the latch pin are fitted is narrowed from top to bottom, it will be effective to suppress the movement of the support frame in the front-back direction.

[0009]

[Operation] If you push the support frame into the case from above,
The mounting piece engages with the stepped portion of the case partition wall in a snap-fit manner and is fixed in the vertical direction, and the latch pin fits in the groove and is fixed in the front and rear direction. In this case, by simultaneously pressing the positioning piece against the abutment portion of the case partition, the fixation in the front and rear direction becomes stronger. In addition, by gradually narrowing the width of the groove in which both ends of the latch pin fit from top to bottom, the latch pin pushed into this groove can be held without any gaps, and the support frame will be affected by the impact when opening and closing. There is no movement at all. Since screws are not used to fix the support frame in this manner, there is no need for a mounting seat for passing the screws through, and there is no need to tighten the screws.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be explained based on the drawings. Incidentally, the same parts as in the conventional example are given the same reference numerals, and the description thereof will be omitted. FIG. 1 shows a support frame, in which (A) is a plan view, (B) is a side view, and (C) is a front view seen from the direction of arrow C in (B). In the figure, the support frame 28 is made by punching out a steel plate and then bending it, and includes a U-shaped integrally formed part consisting of left and right side plates 29 and a bottom plate 30, and a reinforcement welded to the front end part. Part 3
It is composed of 1.

The end of the side plate 29 on the power supply side (the left side in the figure) extends downward, and a pair of mounting pieces 32 are formed in this part in an inverted V-shape and are bent outward in the shape of a tongue. Further, a positioning piece 33 is cut and bent at the end of the load side (right side in the figure) of one side plate 29 and projects diagonally forward. Note that 34, 35, and 36 are support holes into which the latch pin 14, pin 20, and pin 22 are inserted, respectively, and 37 is an escape hole through which the cross bar 24 is passed. Further, reference numeral 38 denotes a support piece bent left and right to support the handle lever 17, and a groove at the tip of the handle lever 17 is fitted onto this support piece 38 (see FIG. 7). Further, the bottom plate 30 is provided with a screw hole 30a.

On the other hand, FIG. 2 shows the case 1, in which (A) is a plan view and (B) is a partially sectional side view taken along line BB in (A). The support frame 28 is housed in the central pole part of the case 1, and the support frame 28 of the partition wall 1a
A stepped portion 39 is provided on the surface facing the mounting piece 32 in correspondence with the mounting piece 32 . This step 39 has a recess 40 (FIG. 2) in the side wall 1a.
(B)), and the stepped portion is a slope, as will be described later. Further, the partition wall 1a is provided with grooves 41 in the vertical direction that fit with both ends of the latch pins 14 that protrude left and right from the side plates 29 of the support frame 28, and furthermore, positioning pieces 33 are press-fitted in the front-back direction (left-right direction in FIG. 2). A pressing portion 42 is provided. Note that the partition wall 1a
is provided with a guide portion 43 that slightly protrudes inward to guide the support frame 28 when it is inserted into the case 1. 1c is a mounting seat similar to the conventional example (FIG. 7).

FIG. 3 shows a support frame 28 in the case 1 of FIG.
It shows the state in which it is attached, (A) is a plan view, and (B) is a partially broken side view. To attach the support frame 28 to the case 1, the support frame 28 is inserted into the case 1 from above while elastically deforming the attachment piece 32 and the positioning piece 33 inward, and is pushed in until the attachment piece 32 falls into the recess 40. At that time, both ends of the latch pin 14 are inserted into the groove 41. As a result, the mounting pieces 32 of the support frame 28 engage with the stepped portions 39 to prevent them from coming off upward, and at the same time, the positioning pieces 33 come into pressure contact with the partition wall 1a and the pressing portion 42 and are pressed against the power supply side. Positioning is performed in the front-back direction. Next, the screw 27 is inserted from the back side of the case 1 and screwed into the screw hole 30a.

FIG. 5 is an enlarged sectional view taken along line V--V in FIG. 3(B). When the mounting piece 32 falls into the recess 40 of the case 1, it opens left and right and engages with the stepped portion 39. In that case, the step 39 is formed into an inclined surface as shown in the figure so that there is no play in the vertical direction between the mounting piece 32 and the step 39. That is, when the mounting piece 32 is elastically opened, it bites into the inclined surface of the stepped portion 39, and play in the vertical direction is absorbed. Further, 44 is a protrusion formed on the bottom surface of the case 1 so that the side plate 29 is not deformed inward by the elastic force that causes the mounting piece 32 to open. To remove the support frame 28 attached to the case 1, after removing the screws 27, a bifurcated removal jig 46 is inserted through a pair of holes 45 provided at the bottom of the case 1. As a result, the mounting piece 32 that has fallen into the recess 40 is pushed inward and removed from the stepped portion 39, and the support frame 28 can be pulled out upward.

FIG. 6 is a longitudinal sectional view showing a circuit breaker using the support frame 28. The opening/closing mechanism 13 is assembled as a unit on the support frame 28 except for the lower link of the toggle link 16 (the link connected to the holder 9).
Case 1 in which current-carrying parts such as movable contact 4 are pre-assembled
Incorporate all together. At this time, the lower link is connected to the holder 9 in advance, and is connected to the upper link (link connected to the latch 15) of the opening/closing mechanism unit that is installed later by the central connecting pin 18.

According to the above configuration, the conventional mounting seat 1b
This eliminates the need for the opening/closing mechanism 13 and the movable space of the movable contact 4 to be narrowed due to the expansion of the partition wall 1a. Support frame 28 by pressure welding
The positioning accuracy in the front-back direction is improved. Furthermore, since the support frame 28 can be attached to the case 1 by simply pushing it in, the screw tightening work is reduced and the assembly work is simplified. In the above embodiment, the mounting piece was provided only on the power supply side of the support frame, and the load side was additionally tightened with one screw, but this screw is not necessarily necessary depending on the position, shape, and size of the mounting piece. Additionally, a mounting piece can be provided on the load side of the support frame.

The groove 41 (FIG. 2) in the above embodiment is formed with the same width from top to bottom, but the figure shows an embodiment in which the width of the groove 41 is narrowed from top to bottom to form a wedge shape. 4. In FIG. 4, the width of the groove 41 is equal to the width of the latch pin 1 at the upper end.
4, but narrows downward in a V-shape and becomes smaller than the diameter of the latch pin 14 at the bottom. By making the groove 41 V-shaped in this way, the latch pin 14 bites into the groove 41 as the support frame 28 is pushed into the case 1, so that the support frame 28 is fixed with no slack in the front-rear direction. become. Such a configuration is extremely effective in preventing a mistrip phenomenon in which the support frame 28 moves in the front-back direction due to the impact during the opening/closing operation, causing the latch receiver 21 to disengage from the claw 23 of the cross bar 24.

[0018]

[Effects of the Invention] According to the present invention, since there is no need to use screws to attach the support frame of the opening/closing mechanism to the case, the space for tightening the screws does not narrow the space in which the opening/closing mechanism or the movable contactor can move. It becomes easier to design these parts. Furthermore, the positioning accuracy of the support frame in the front and back direction is improved, and the screw tightening work is reduced, making assembly easier.

[Brief explanation of the drawing]

FIG. 1: (A) is a plan view of a support frame in an embodiment of the present invention, (B) is a side view thereof, and (C) is a C of (B).
It is a front view seen from the direction.

FIG. 2(A) is a plan view of a case in an embodiment of the present invention, and FIG. 2(B) is a partially sectional side view taken along line BB in FIG. 2(A).

3A is a plan view of the support frame of FIG. 1 attached to the case of FIG. 2, and FIG. 3B is a partially cutaway side view thereof.

FIG. 4 is a side view corresponding to FIG. 3(B) of an embodiment in which the width of the groove in the case partition wall is narrowed from top to bottom.

FIG. 5 is a sectional view taken along line V-V in FIG. 3(B).

FIG. 6 is a longitudinal sectional view of a circuit breaker showing an embodiment of the invention.

FIG. 7 is a vertical cross-sectional view of a circuit breaker showing a conventional example.

8(A) is a plan view of the conventional case of FIG. 7 with a support frame attached thereto, and FIG. 8(B) is a partially cutaway side view thereof.

[Explanation of symbols]

1 Case 4 Movable contact 13 Opening/closing mechanism 28 Support frame 29 Side plate 32 Mounting piece 33 Positioning piece 39 Stepped section 41 Groove 42 Pressing part

Claims (3)

[Claims] 1. A circuit breaker in which a support frame having side plates on both left and right sides is attached to a case, and an opening/closing mechanism for opening and closing a movable contact is supported on this support frame,
Parts of the left and right side plates of the support frame are each cut outward into a tongue shape to form an inverted V-shaped mounting piece, and the support frame is inserted into the case from above onto the surface of the case partition facing the side plate. A mounting device for an opening/closing mechanism support frame in a circuit breaker, characterized in that it has a stepped portion that engages the mounting piece, and a groove that fits both ends of a latch pin that supports a latch of the opening/closing mechanism on the side plate. 2. The device according to claim 1, wherein a positioning piece is formed at an end of the side plate of the support frame and projects diagonally forward, and a pusher is used to press the positioning piece against a surface of the case partition facing the side plate. A mounting device for a support frame of an opening/closing mechanism in a circuit breaker, characterized by being provided with this part.
3. The device according to claim 1 or 2, wherein the width of the groove in the case partition into which both ends of the latch pin are fitted is gradually narrowed from top to bottom. Mechanism support frame mounting device.