JPH0220747Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention relates to circuits and disconnectors,
The present invention relates to a relatively small circuit or disconnection device such as a safety breaker, in which the structure of the tripping device is improved.

[Conventional technology]

Conventionally, this type of circuit breakers and breakers have been disclosed, for example, in Japanese Patent Application Laid-open No. 51-53274 and Japanese Patent Publication No. 51-13220.

[Problem that the invention attempts to solve]

The above-mentioned conventional circuit breakers have a problem in that due to variations in the accuracy of the component parts, the lever swings horizontally, making it impossible to obtain stable tripping characteristics.

The purpose of this invention is to eliminate the above-mentioned problems of the conventional circuit and to obtain a circuit breaker that provides stable tripping characteristics.

[Means for solving problems]

The circuit breaker according to this invention includes a plate-shaped lever whose rear end is formed in an arc shape in the width direction, and an engaging portion that engages the lower surface of the rear end of the lever by surface contact. It is equipped with a trip lever.

[Effect]

The circuit breaker of this invention has the rear end of the lever formed into an arc shape in the width direction, and the lower surface of the rear end of the lever is engaged by surface contact with the engaging part of the tripping rod.
Prevents variations in accuracy due to horizontal swing of the lever.

〔Example〕

An embodiment of this invention will be described below with reference to the drawings.

FIG. 1 is a side sectional view showing an embodiment of the circuit breaker and circuit breaker according to this invention. FIG. 2 is an exploded view of the opening/closing mechanism shown in FIG. 1. In FIGS. 1 and 2, a base 1 and a cover 2 are both made of synthetic resin and constitute the outer shell of the breaker. The frame 3 is formed into a substantially L-shape, and the vertical plate portion 3
A is used for mounting opening/closing mechanism parts as will be described in detail later, and the bottom plate part 3b is fixed to the base 1 with machine screws 4. The handle 5 accommodates the upper part of the frame 3 in an inner groove 5a, and is rotatably supported by a shaft 6 in a round hole 3c of the frame 3. Both ends of the shaft 6 are inserted into guide grooves (not shown) of the cover 2 with the handle 5 assembled to the frame 3. The upper arm 7a of the U-shaped pin 7 is fitted into a hole 5b at the tip of the handle 5, and the lower arm 7b is fitted into a hole 8b of the lever 8 and an elongated hole 3d of the frame 3. The detailed shape of the lever 8 is shown in FIGS. 3a to 3c.

FIG. 3a is a plan view of the lever 8, and FIG. 3b is a plan view of the lever 8.
Figure 3a is a side view, and Figure 3c is a rear view of Figure 3a. In FIGS. 3a to 3c, the lever 8 is formed in a substantially U-shape, and both hanging plates 8a are provided with a round hole 8b through which the lower arm 7b of the U-shaped pin 7 is inserted. is provided with a narrow rectangular hole 8c into which the upright plate portion 3a of the frame 3 is loosely fitted, and the rear end portion 8d is substantially centered approximately at the center of both round holes 8b in plan view as shown in FIG. 3a. A rounded shape is formed by a circular arc with a radius of A. The handle spring 9 is attached to the inner groove 5 of the handle 5.
a, insert the shaft 6 into the coil part, and insert the front leg 9.
The tip of a is formed into a substantially semicircular arc shape, and is hooked to the upper arm 7a of the U-shaped pin 7 in the inner groove 5a, and the hind leg 9
b is locked by a locking portion 3e of the frame 3 to bias the handle 5 clockwise. The legs 9a are adapted to pull the upper arm 7a toward the axis 6 when the upper leg 9a is engaged with the upper arm 7a. The presser plate 10 is made of synthetic resin, and is installed so that it fits into the groove 1a of the base 1, is biased upward by a push spring 11, and is moved up and down with its upper portion pressed by a lever 8. The tripping rod 12 is made of synthetic resin, and has a support shaft 12a rotatably supported in the U-shaped groove 1b of the base 1 as shown in FIG. 4, and its attached state is shown in FIG. As shown in FIG.
and a narrow groove portion 12d for mounting the leaf spring 13, which will be described later.
and a locking portion 12e, and a convex portion 12f for preventing the tripping rod 12 from tilting forward when the circuit or disconnector is in the open state. The leaf spring 13 has a substantially L-shape as shown in FIGS. 2 and 5, and is able to trip the vertical plate 13a and
The horizontal plate 13b is fitted into the narrow groove 12d of the base 1, and the horizontal plate 13b is locked to the locking part 1c of the base 1. is the support shaft portion 12a
It is biased counterclockwise using the fulcrum as the fulcrum. Note that the leaf spring 13 has a cut-out projection 13c formed at the tip of the vertical plate 13a, and is locked to a locking portion 12e adjacent to the narrow groove portion 12d, so that it will not come off when fitted. One end of the movable element 14 is fixed to a movable element attachment part 3f extending from the bottom plate 3b of the frame 3, and the almost central part is connected to the cut groove 1 of the above-mentioned presser plate 10.
0a, and a movable contact 15 is inserted at the movable free end.
is fixed. Bimetal 16 is mover 14
It is fixed to the movable element attachment part 3f, and its tip bends to the right in FIG. , trip rod 12
is rotated clockwise against the biasing force of the leaf spring 13. The terminal device 17 is mounted on the base 1 and is used to connect an electric wire (not shown) on the power supply side to be connected to a circuit or a disconnector. Flexible copper stranded wire 1
8 has one end fixed to the terminal device 17 and the other end fixed to the bimetal 16 to connect the two. The terminal plate 19 is attached to the base 1. The fixed contact 20 is fixed to the terminal plate 19 at a position corresponding to the movable contact 15. The terminal device 21 accommodates the other end of the terminal plate 19,
It connects the load-side electric wire (not shown) that is connected to the circuit or disconnector.

Next, the operation of the circuit and disconnector constructed as described above will be explained. In the closed state of the circuit and breaker shown in FIG. 1, the current flows from terminal device 17 → flexible copper stranded wire 18 → bimetal 16 → mover 14 → movable contact 15 → fixed contact 20 → terminal plate 19 → terminal device 21, and the tip of the bimetal 16 curves to the right in FIG. 1 due to the heating action of the current.
Now, when an overcurrent exceeding a predetermined value flows, the tip of the bimetal 16 engages with the engaging portion 12c of the tripping rod 12, causing the tripping rod 12 to rotate clockwise. When the tripping rod 12 rotates clockwise, the tripping rod 12
The engagement portion 12b of the lever 8 is disengaged from the rear end portion 8d of the lever 8, and the lever 8 is pressed against the pusher spring 1 via the presser plate 10.
1, the U-shaped pin 7 rotates clockwise around the lower arm 7b as a fulcrum. Therefore, the presser plate 10
moves upward, and the movable element 14 inserted through the cut groove 10a of the holding plate 10 also ascends, and the movable contact 15
is opened from the fixed contact 20. As described above, when an overcurrent flows, the circuit breaker automatically opens from the closed state shown in FIG. 1. Subsequently, the handle 5 is biased clockwise by the handle spring 9, so the U-shaped pin 7 moves upward along the elongated hole 3d of the frame 3, thereby pushing the rear end of the lever 8. 8d is the engagement part 12b of the tripping rod 12
It disengages and rises upward, and comes to rest near the convex portion 12f. Therefore, the current is cut off and bimetal 1
6 returns to its original position, the tripping rod 12 releases the leaf spring 1
3 rotates counterclockwise, resulting in the state shown in FIG. Therefore, if the handle 5 is rotated counterclockwise from this state, the U-shaped pin 7 will move downward along the elongated hole 3d of the frame 3, and at this time it will be pulled into contact with the rear end 8d of the lever 8. The engaging portion 12b of the lever 12 engages, and the lever 8 engages with this engaging portion 12.
Using b as a fulcrum, press the presser plate 10, push it down against the spring 11, and enter the state shown in FIG. 1 to close the circuit.

Next, the shape of the rear end portion 8d of the lever 8 will be explained. The engagement between the rear end 8d of the lever 8 and the engagement portion 12b of the tripping rod 12 is such that the rear end 8d always engages with the engagement portion 1.
2b to the deepest part to find the predetermined stopping position of the tripping rod 12. Conventionally, the tripping rod 1
The predetermined stopping position of the lever 8 is determined by bringing the upper part of the frame 3 into contact with the upper part of the tripping rod 12. Since the predetermined stopping position of the tripping rod 12 is directly determined by the engagement with the engaging portion 12b,
Very stable. Also, the narrow square hole 8 of the lever 8
Since there is a gap between the frame 3 and the frame 3 in the width direction of the narrow square hole 8c, the lever 8 moves slightly in the direction perpendicular to the paper plane in FIG. Therefore, by providing the rear end portion 8d of the lever 8 in the plan view of FIG. 3a with a rounded shape with a radius A, the lever 8 can be moved in a direction perpendicular to the plane of the paper in FIG. 12
Try to eliminate the impact on That is, when the rear end 8d of the lever 8 does not have a rounded shape with a radius A, for example, when the handle 5 is turned on, the state changes from the state shown in FIG. 7a to the state shown in FIG. 7b or FIG. 7C. The rear end 8d of the lever 8 moves left and right, as shown in FIGS.
The pushing distance B of the tripping rod 12 shown in FIG. 7 changes compared to FIG. 7a, and the tripping rod 12 is pushed. As a result, the first
The gap G shown in the figure changes and the tripping time fluctuates.

FIG. 8 is a perspective view showing another mounting state of the movable element 14. That is, in the embodiment shown in FIGS. 1 and 2, the frame 3 is provided with a movable element mounting part 3f, and the movable element 14 and the bimetal 1
However, in the embodiment shown in FIG.
and bimetal 16 are attached. Note that a through hole may be provided in place of the cutout groove 10a of the holding plate 10.

[Effect of idea]

As described above, according to this invention, the rear end of the plate-shaped lever is formed into an arc shape in the width direction, and the lower surface of this rear end is brought into surface contact with the engaging part of the tripping rod. The tripping rod does not rotate even when horizontal shaking occurs, and the gap between the tripping rod and the bimetal remains constant, thereby preventing variations in the tripping characteristics due to horizontal shaking of the lever. has.

[Brief explanation of the drawing]

Fig. 1 is a side cross-sectional view showing an embodiment of the circuit breaker and circuit breaker in the closed state according to this invention, Fig. 2 is an assembled exploded view of the opening/closing mechanism shown in Fig. 1, and Fig. 3a is a plan view of the lever. Figure 3b is a side view of Figure 3a, Figure 3c is a rear view of Figure 3a, Figure 4 is a perspective view showing the main parts of the base, and Figure 5 is the assembly of the tripping rod. FIG. 6 is a side sectional view showing the open circuit state of the circuit and disconnector according to this invention, FIG. 7 is an explanatory diagram of the effect of this invention, and FIG. It is a perspective view showing an example. In the figures, the same parts in each figure are given the same reference numerals: 1 is the base, 2 is the cover, 3 is the frame, 3a is the standing board, 3c is the round hole, 3d is the elongated hole, 5
is the handle, 5a is the inner groove, 5b is the hole, 6 is the shaft, 7
is a U-shaped pin, 7a is an upper arm, 7b is a lower arm, 8 is a lever, 8b is a round hole, 8c is a narrow square hole, 8d is a rear end, 10 is a holding plate, 10a is a cut groove, 11 is a push spring , 12 is a tripping rod, 12b is an engaging portion, 13
is a leaf spring, 13a is a vertical plate, 13b is a horizontal plate, 13c
14 is a projection, 14 is a movable element, 15 is a movable contact, 16 is a bimetal, 19 is a terminal plate, and 20 is a fixed contact.

Claims (1)

[Claims for Utility Model Registration] A terminal plate fixed to a base and having a fixed contact at one end; a mover having a movable contact at one end opposite to the fixed contact; and an intermediate portion of the mover. a holding plate having a cut groove or a hole inserted therethrough and opening and closing the movable contact with respect to the fixed contact; and a holding plate installed between the holding plate and the base to separate the holding plate from the base. a handle that is opened and closed when the movable contact and the fixed contact are manually opened and closed; and a front end that presses the upper end of the presser plate when the handle is closed; a plate-shaped lever that is rotatably supported with an intermediate portion as a fulcrum and whose rear end portion is formed into an arc shape in the width direction; It has an engaging part that engages in surface contact with the lower surface of the rear end, and the upper end engages with a bimetal that curves when an overcurrent flows, thereby connecting the rear end of the lever and the engaging part. A circuit breaker equipped with a trip lever for releasing engagement.