JPH0624118Y2 - Circuit breaker - Google Patents

Description

[Detailed Description of the Invention] Industrial field of application The present invention relates to a circuit breaker, which is mainly for low voltage and detects an overcurrent or a short-circuit current when an electric device or a circuit wiring has an accident, and cuts the circuit to supply power and load. It's something you want to protect.

Conventional technology This type of circuit breaker has already been widely spread and used, but recently, with the electronicization of load equipment, the demand for miniaturization of this type of circuit breaker is increasing, and the mechanism is simplified. It is proposed that the parts are reduced.

The conventional circuit breaker will be described below with reference to FIG. 1 showing a closed state and FIG. 2 showing a closed state.

In the figure, 1 is an insulating base, 2 is a power supply side terminal whose other end is connected to a power supply, 3 is a fixed contactor that can be fixed to the tip of the power supply terminal 2, and 4 is a movable contact that opens and closes with respect to the fixed contactor 3. The contactor, 5 is an insulative operation handle rotatably supported on the insulating base 1 by the handle shaft 6 in the central part, and the movable contactor 4 is fixed to one end of the insulating operation handle 7, and the other end is engaged with the operation handle 5. It is an open / close contact rod. The reference numeral 8 designates a substantially inverted U-shaped tripping rod pivotally attached to a shaft 9 which is planted on the insulating base 1, and has a central hole 10 and a middle portion of the opening / closing contact rod 7 between the projection 38. A breaking spring 11 is stretched over the other end, and the other end claw portion 12 is engaged with the cutout portion 16 of the trip plate 15. The trip plate 15 is axially supported by the insulating base 1 by the support shaft 13, is biased clockwise by the spring 14, and
Numeral 7 is a bimetal, one end of which is joined to a bent portion 20 in which the upright portion of the load side terminal 18 fixed to the insulating base 1 is cut out, and the other end of which is extended corresponding to the bent portion 21 of the trip plate 15. The tip portion 22 is connected to the opening / closing contact rod 7 by a flexible conductive stranded wire 23. Reference numeral 24 designates a U-shaped iron frame for instantaneous trip, which is fixed to the load terminal 18 by a screw 25 so as to correspond to the middle part of the trip plate 15, and the bimetal 17 is interposed between the trip plate 15 and the trip plate 15. When an accident such as a short circuit occurs in the load circuit and a large current flows through the bimetal 17, it has a function of attracting the trip plate 15 by electromagnetic force and instantaneously cutting it off. Reference numeral 26 is an adjusting screw, which is screwed to the upright portion 19 of the load side terminal 18 and presses the bent portion 20 to adjust the operating current value of the bimetal 17, and 27 is an arc runner for separating the movable contactor 4. The arc is ignited along with the arc, and the arc is extinguished while cooling and suppressing the heat radiation. 28 is a kick insulator that is pivotally supported by a pivot 29 that is planted in the insulating base 1 and is long in the center. The holes 33 and 35 are provided, and the protrusion 37 is provided below. Further, 39 is an insulating wall, which guides the arc generated between the fixed and movable contactors 3 and 4 to the discharge hole 31 when the circuit breaker is cut off, and suppresses the sudden rise of the internal pressure to prevent the trip rod 8, The final operating position of the other end claw portion 12 of the tripping rod 8 that rotates when shutting off is protected to a position that does not hinder the resetting operation after shutting off while protecting the internal mechanisms such as the trip plate 15 and the bimetal 17 It is provided as a stopper. Further, the insulating wall 39 is formed integrally with the insulating base 1 in a state of being erected, and its height is up to a position in contact with the inner surface of the upper lid (not shown) of the circuit breaker in order to achieve the above-mentioned purpose of protecting the mechanism. The wall thickness of the insulating wall 39 is set high and the tripping rod 8
In order to prevent damage caused by the impact of the rotation of the open / close contact rod 7, the thickness is set to be thick in consideration of the molding efficiency during the molding process.

Therefore, the opening distance between the fixed and movable contactors 3 and 4 during the cutting operation depends on the thickness of the insulating wall 39.
The thicker the wall thickness, the shorter the opening distance and the lower the cutting performance, and the thinner the thickness, the damage is caused by the impact of the opening / closing contact rod 7 and the tripping rod 8 which rotate during the cutting. There is a demand for a circuit breaker which has the above-mentioned problems, solves such problems with a simple structure, and has achieved miniaturization and improved breaking performance.

In consideration of such a point, the present invention has a trip rod 8 pivotally mounted on a shaft 9 erected on the insulating base 1, and has a central hole 10 and an opening / closing contact rod. A breaking spring 11 is stretched in the middle of 7, and the movable contactor 4 of the opening / closing contactor rod 7 is fixed to the fixed contactor 3.
On the other hand, when a circuit breaker which is opened and closed by contact is cut off, a metal plate 40 which can be partially bent in an inverted V shape is provided on a stopper part which regulates the final rotation position of the other end claw part 12 of the trip rod 8. It will be.

As described above, according to the present invention, the internal mechanism such as the trip rod 8 and the opening / closing contact rod 7 is protected from the arc generated when the circuit breaker is cut off, and the other end claw portion 12 of the trip rod 8 is rotated at the final position. The stopper portion provided for the purpose of restricting the position is provided with a metal plate 40 which can be partially bent in an inverted V shape to prevent the stopper portion from being damaged and to increase the opening distance.

EXAMPLE Next, the circuit breaker of the present invention will be described with reference to the drawings. FIG. 3 shows a closed state and FIG. 4 shows a closed state, both of which are front views with the upper lid removed, and FIGS. [Fig. 3] is a top view and a side view of a metal plate 40 according to the present invention, which is partially bendable in an inverted V shape.

Therefore, the point that the circuit breaker of the present invention is different from the conventional one is that the internal mechanism such as the trip rod 8 is protected from the arc generated when the circuit breaker is cut off, and the other end claw portion 12 of the trip rod 8 is protected.
In place of the stopper insulating wall 39 provided for the purpose of restricting the final turning position of, the thin metal plate 40 which can be partially bent into an inverted V shape is sandwiched between the insulating base 1 and the upper lid (not shown). . That is, as shown in FIGS. 5A and 5B, the ears 4 that can be projected at four places on the left and right of the center of the metal plate 40 are formed.
A rectangular rectangular plate having 1 is bent into an inverted V shape and is planted and sandwiched in a recess (not shown) provided in the insulating base 1 and the upper lid corresponding to these ears 41. The internal mechanical parts are the same as conventional ones.

The operation will be described below. When an overcurrent flows in the closed state shown in FIG. 3 of the circuit breaker including the metal plate 40 having such a structure, the bimetal 17 acts and the tip 22 of the bimetal 17 acts on the trip plate 15. The trip plate 15 rotates counterclockwise around the support shaft 13 against the spring 14 in contact with the bent portion 21, and the claw portion 12 of the tripping rod 8 causes the trip plate 1 to move.
5, the tripping rod 8 is rotated clockwise about the shaft 9 by the pulling force of the breaking spring 11 to rotate the claw portion 1
2 abuts and attaches to the metal plate 40. On the other hand, with the rotation of the trip rod 8, the pressure contact acting force in the circuit closing direction exerted on the open / close contact rod 7 of the cutoff spring 11 is weakened, and at the same time, the pin 34 erected on the trip rod 8 makes the kick insulator 28 longer. The kick insulator 28 is rotated counterclockwise about the pivot 29 through the hole 35, and the protrusion 37 of the kick insulator 28 pushes the open / close contact rod 7 to push it away, and the subsequent trip rod 8 Complete rotation, that is, when the other end claw portion 12 of the tripping rod 8 reaches the final position where it abuts the metal plate 40, the opening direction acting force exerted on the open / close contact rod 7 of the cutoff spring 11 exceeds the dead center of the toggle mechanism. Is increased by the movable contactor 4
Rapidly separates to the position where the
The arc generated between the movable contacts 3 and 4 is guided to the discharge hole 31 to complete the interruption.

The reset operation after the interrupting operation, the opening operation by the normal operation handle 5, and the short-circuit interrupting operation when the load is short-circuited are performed by the conventionally known technology, and therefore detailed description thereof will be omitted here.

Effect of the Invention As described above, in the present invention, by providing the metal plate 40 that can be partially bent in an inverted V shape to the stopper portion that regulates the final rotation position of the other end claw portion 12 of the tripping rod 8 at the time of cutting, A machine that guides an arc generated by the opening of the movable contactor 4 to the discharge hole 31 to protect the internal mechanism such as the trip rod 8 and the trip plate 15 and rotates the open / close contact rod 7 and the trip rod 8. It is possible to prevent breakage of the stopper portion due to mechanical impact, and further reduce the thickness of the stopper portion as compared with the case where the stopper portion is molded. Therefore, the opening distance at the time of interruption is increased by that thickness. In addition, it has the effect of being able to achieve the improvement of the blocking performance.

[Brief description of drawings]

FIGS. 1 and 2 are conventional front views, and FIGS. 3 and 4 are front views of the circuit breakers according to the present invention with the upper lids removed so that the inside can be seen. FIGS. , 4 show the state where the movable contact is opened in response to the overcurrent.
Further, FIG. 5 shows the outer shape of the inverted V-shaped metal plate, (a) is its front view and (b) is a side view. In the figure, 2 is a power terminal, 3 is a fixed contact, 4 is a movable contact,
7 is an opening / closing contact rod, 8 is a trip rod, 9 is a shaft, 10 is a central hole, 11 is a blocking spring, 12 is the other end claw of the opening / closing contact rod 7, 15 is a trip plate, 16 is a trip plate 15 is a notch, 40 is an inverted V-shaped metal plate, and 41 is an ear.

Claims (1)

[Scope of utility model registration request] 1. An insulating base 1 is provided with a trip rod 8 pivotally mounted on a shaft 9, and a breaking spring 11 is stretched between the center hole 10 and the opening / closing contact rod 7. In a circuit breaker in which the movable contactor 4 of the open / close contactor rod 7 comes into contact with and separates from the fixed contactor 3, a stopper portion for regulating the final rotation position of the other end claw portion 12 of the tripping rod 8 at the time of interruption. A circuit breaker in which a metal plate 40 that can be partially bent in an inverted V shape is provided.