JPH07230753A - Inertial delay device for circuit breaker - Google Patents

Abstract

PURPOSE:To provide an armature such that its common use can be attained in also a circuit breaker without an inertial delay device, in the inertial delay device for delaying response action of the armature in an overcurrent trip gear by an inertial disk. CONSTITUTION:A point end of an armature 1 is partly extended to the front, and this extended part 1e is interposed by two protruding pins 2a provided parallelly to a side surface of an inertial disk 2, so as to connect the armature 1 and the inertial disk 2. Since the extended part 1e is very fine with small mass, a hazard by this part, worsening impact resistance performance of a circuit breaker without an inertial delay device and changing an operating characteristic, is eliminated, and the armature 1 having this extension part 1e can be left as in common use in the circuit breaker without the inertial delay device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is attached to an electromagnetic overcurrent trip device for a circuit breaker used to protect various devices, and delays the response to a pulsed overcurrent to avoid unnecessary electric circuit interruption. The present invention relates to an inertial delay device.

[0002]

2. Description of the Related Art In a motor circuit, for example, a starting current of several tens of times the rated current flows at a time of starting the motor for a very short time, but in order to prevent the trip operation of the circuit breaker due to such pulse-like overcurrent, The inertial delay device that delays the response of the armature of the electromagnetic overcurrent trip device built in by using the inertial disk is used. FIG. 7 is an exploded perspective view showing a main part of a conventional configuration. In the figure, an armature 1 of an electromagnetic overcurrent trip device is provided with a bent piece 1a in an L shape on one side of its tip, and a U-shaped hole 1b is formed in this bent piece 1a. On the other hand, a projecting pin 2a is press-fitted to the end face of the inertia disk 2 having a shape in which a part of a circle is cut out. The inertial disk 2 is rotatably supported by a support shaft (not shown) passing through the bearing hole 2b, and its protruding pin 2a is U as shown by a chain line arrow.
The armature 1 is connected by being inserted into the character hole 1b.

Since the armature 1 is connected to the inertial disc 2, the movement of the armature 1 is slowed against the same electromagnetic attraction force. Therefore, when a pulsed overcurrent flows through the circuit breaker, if the armature 1 is alone, it is immediately attracted and the circuit breaker trips.
Because of this, the response is delayed, and the overcurrent disappears before the stroke required for tripping is drawn, and trip does not occur.

[0004]

In such a conventional structure, a bending piece 1a is provided at the tip of the armature 1. The bending piece 1a has a U-shaped hole 1b that allows the protruding pin 2a to be inserted. Requires a considerable amount of size to be formed and therefore its mass is also considerable. As a result, when the armature 1 is used as a circuit breaker without an inertia delay device, the bending piece 1
Due to the mass of “a”, the specified impact resistance performance (do not mistrip even if a constant shock such as a drop is applied to the circuit breaker) cannot be satisfied, and the magnetic flux passing through the armature 1 is biased toward the bending piece 1a side. However, there is a problem that the operating characteristics change.

Therefore, conventionally, the circuit breaker with the inertial delay device is shown in FIG. 7, and the circuit breaker without the inertial delay device is such that the bending piece 1a shown in FIG. 8 is not provided. , Management was complicated.
When the inertial delay device is included, the mass of the bending piece 1a is smaller than that of the inertial disk 2, and the operation of the armature 1 is slow, so that the presence or absence of the bending piece 1a does not occur. Therefore, an object of the present invention is to provide an inertial delay device for a circuit breaker in which it is not necessary to properly use the armature depending on the presence or absence of the inertial delay device, which simplifies component management and reduces the cost. is there.

[0006]

In order to achieve the above object, the present invention provides a bifurcated protrusion on the side surface of an inertial disc and extends a part of the tip of the armature forward, Should be sandwiched between the protrusions. As the bifurcated protrusion, it is preferable to provide two parallel pins on the side surface of the inertial disk. Further, if the inertial disk and the protrusion are integrally molded with a resin material filled with non-magnetic metal powder, the manufacture becomes simple.

[0007]

In the present invention, a part of the tip of the armature is extended, and the extended portion is sandwiched by the bifurcated protrusions provided on the side surface of the inertial disc. The extension of the armature in such a structure is smaller than the conventional bent piece in which the protruding pin is inserted, and the mass is small. Therefore,
This extension does not substantially affect the impact resistance performance and operation characteristics of the armature, and the armature having this extension can be used as it is for a circuit breaker without an inertia delay device.

By the way, the inertial disk is generally manufactured by cutting using a non-magnetic metal material having a large specific gravity, such as brass or lead, but if it can be integrally molded from resin, the processing cost will be low and the dimensional accuracy will be high. Become. In this case, the resin itself has a small specific gravity, but the non-magnetic metal powder can be filled to increase the specific gravity to the level of a metal.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. Here, FIG. 1 is a side view of a main part of a circuit breaker equipped with an inertial delay device, FIG. 2 is a side view of the circuit breaker of FIG. 1 in the OFF state, and FIG. 3A is an inertial delay device. FIG. 4 is a plan view of the apparatus, FIG. 4B is a side view thereof, FIG. 4 is a side view of the overcurrent trip device, FIG. 5 is a perspective view of a main part of the armature in FIG. 4 and an inertia disk connected to the armature, and FIG. (A) is a side view showing an embodiment in which the inertial disk is different, (B)
Is a plan view thereof. The same reference numerals are used for the parts corresponding to those of the conventional example.

First, in the inertial delay device 3 of FIG. 3, the inertial disk 2 is rotatably supported by a support 4 by a support shaft 5. The support 4 is made of a plate material, and mounting legs 4a and 4b that are press-fitted into the case of the circuit breaker are bent and formed in two places as will be described later. A hemispherical projection is provided by extrusion for the purpose of reducing the number of holes and preventing it from coming off.
The support shaft 5 has a head, is inserted through the stepped hole 2b (FIG. 5) of the inertial disk 2, and is fixed to the support 4 by caulking through the small diameter portion at the tip. The inertial disk 2 is made of brass and has the same shape as the conventional one, but two protruding pins 2a are provided in parallel, and these protruding pins 2a are fixed to the inertial disk 2 by press fitting. The distance between the two protruding pins 4a is slightly larger than the plate thickness of the armature 1 described later.

The inertial disk 2 shown in FIG. 6 has the same shape as that shown in FIG. 3, but this inertial disk 2 has the same high specific gravity as brass by being filled with the non-magnetic metal powder integrally with the protruding pin 2a. It is made of resin. The inertia disk 2 has a small diameter of, for example, about 7 mm and a thickness of about 2.5 mm, and the protruding pin 2a has a small diameter of about 0.8 mm. Therefore,
It is impossible to integrally form these from non-magnetic metal such as brass by press working because of the strength of the mold, etc. Normally, the inertial disk 2 and the protruding pin 2a are separately manufactured by cutting, and the inertial disk 2 is manufactured. Projecting pin 2a in the small mounting hole
Is pressed in and fixed. Therefore, if the resin is integrally molded as shown in the drawing, the manufacturing is simplified, and the variation in the shape is eliminated, so that the performance is stabilized.

On the other hand, the electromagnetic type overcurrent trip device 6 shown in FIG.
2, an electromagnetic coil 9 is arranged so as to surround a cylinder 8 fixed to an L-shaped yoke 7, and an armature 1 is attached to the yoke 7 so as to face an armature 10 that closes the head of the cylinder 8. The armature 1 is composed of a strip-shaped plate material, and a pair of arms 1c bent and formed in a U shape on both sides of one end thereof are combined with a pair of arms 7a bent and formed on both sides of an upper end of the yoke 7, and penetrate these. It is rotatably supported by a shaft pin 11.

An arm 1c on one side of the armature 1 is integrally provided with an angular operation portion 1d which acts on a tripping mechanism of a circuit breaker as will be described later, and is opposite to the armature operation piece 1d of the yoke 7. On the arm 7a on the side of the
b is integrally provided. Then, the operating portion 1d and the spring receiving projection 7b are engaged with both legs of a return spring 12 formed of a torsion spring mounted on the shaft pin 11, and the armature 1 is rotated counterclockwise in the figure by its spring force. It is urged and stopped in the posture shown. Here, as shown in FIG. 5, a part of the armature 1 on the side closer to the inertial disk 2 is extended forward, and a rectangular extension 1e is provided. The extension portion 1e is sandwiched by the two protruding pins 4a of the inertial disc 4 in a state where the inertial delay device 3 is mounted, as shown by a chain line arrow.

The inertial delay device 3 is not attached to the circuit breaker of FIG. Although the drawing shows the OFF state, in the ON state, the current flows from the terminal plate 13 to the lead wire 14 and the movable contact 1.
5, the fixed contact 16 and the electromagnetic coil 9 of the overcurrent trip device 6 to the terminal plate 17. When the operation handle 18 is tilted clockwise in the figure in the OFF state, the movable contact 15 comes into contact with the fixed contact 16 by the operation of the opening / closing mechanism 19, and the circuit breaker is turned on. When an overcurrent (short-circuit current or overload current) passes through the circuit breaker in the ON state, the overcurrent trip device 6 operates, the armature 1 is attracted to the armature 10 and the shaft pin 11 is used as a fulcrum to rotate clockwise. Turn to.
Along with this, the operation portion 1d of the armature 1 pushes down the trip lever 20 to release the lock of the opening / closing mechanism 19. As a result, the opening / closing mechanism 19 opens the movable contact 15 to turn off the circuit breaker.

FIG. 1 shows a state in which the inertial delay device 3 is mounted on the circuit breaker. In FIG. 2, the case of the circuit breaker is provided with mounting grooves 21 and 22 in accordance with the mounting legs 4a and 4b of the inertial delay device 3. Therefore,
The inertia delay device 3 is attached to the circuit breaker shown in the figure with the cover removed.
And the mounting legs 4a and 4b are press-fitted into the mounting grooves 21 and 22, respectively. At that time, the extension 1e at the tip of the armature 1 is sandwiched between the two protruding pins 2a of the inertial disk 2. As a result, the inertial delay device 3 is mounted as shown in FIG. When a pulse-like overcurrent flows through the circuit breaker, if the armature 1 alone is immediately attracted and the circuit breaker is turned off, when the inertial delay device 3 in FIG. 1 is mounted, the armature 1 is projected by the protruding pin 2a. Since the inertial force of the sandwiched inertial disk 2 cannot respond immediately, the circuit breaker does not turn off if the pulse width of the overcurrent is less than a certain value.

In the structure shown in the above-mentioned embodiment, the extension portion 1e provided on the armature 1 is sandwiched by the projecting pin 2a, so that the U-shaped hole 1b is inserted through the projecting pin 2a.
It has a very small size and a small mass as compared with the conventional bent piece 1a having Therefore, even if the armature 1 with the inertial delay device having the extension portion 1e is used as it is for a circuit breaker without the inertial delay device, there is no fear that the impact resistance performance is deteriorated by the large mass of the armature tip.
Moreover, there is no fear that the tripping characteristics will be affected by the bias of the magnetic flux. In that case, as shown in FIG. 7, the inertial disc 4 is made of a resin whose specific gravity is increased to that of a metal by filling it with a non-magnetic powder.
If the and the projecting pin 4a are integrally formed, the number of manufacturing steps is reduced as compared with the case of manufacturing by cutting, and the variation in shape is reduced to stabilize the performance. In the illustrated embodiment, the two parallel protruding pins 4a are used as the bifurcated protrusions sandwiching the extension 1e of the armature 1. However, the U-shaped groove is formed in the plate-shaped protrusion so that the shape is appropriate. Can be changed.

[0017]

According to the present invention, since the extension for connecting the armature to the inertial disk is very small, the armature having this extension can be used as it is in a circuit breaker without an inertia delay device. The impact resistance is not impaired and the operating characteristics do not change. Therefore, it is not necessary to properly use the armature depending on the presence or absence of the inertial delay device, the number of parts is reduced, the management is facilitated, and the cost is reduced. In that case, if the inertial disk and its bifurcated protrusion are integrally molded using a resin filled with non-magnetic metal powder and having a high specific gravity, the cost will be reduced due to the reduction of manufacturing man-hours and the dimensional accuracy will be improved. Stabilizes the tripping property.

[Brief description of drawings]

FIG. 1 is a side view of a main part of a circuit breaker showing an embodiment of the present invention.

FIG. 2 is a side view showing the overall configuration of the circuit breaker of FIG.

3A and 3B show the inertial delay device in FIG. 1, in which FIG. 3A is a plan view and FIG. 3B is a side view.

4 is a side view of the overcurrent trip device in FIG. 1. FIG.

5 is an exploded perspective view of a main part of an armature and an inertial disk shown in FIG. 1. FIG.

FIG. 6 shows inertial disks of different embodiments of the present invention,
(A) is a side view and (B) is a plan view.

FIG. 7 is an exploded perspective view of a main part of an armature and an inertial disk showing a conventional example.

FIG. 8 is a perspective view of an essential part showing an armature of a circuit breaker without an inertial delay device.

[Explanation of symbols]

 1 Armature 1e Extension part 2 Inertial disk 2a Projecting pin. 3 Inertial delay device 6 Overcurrent trip device

Claims (3)

[Claims] 1. An inertial delay device for a circuit breaker in which the response of an armature of an electromagnetic overcurrent trip device is delayed by an inertial disk, and a bifurcated protrusion is provided on a side surface of the inertial disk and a part of a tip of the armature is provided. An inertial delay device for a circuit breaker, characterized in that the extension is extended forward and the extension is sandwiched by the protrusions. 2. An inertial delay device for a circuit breaker according to claim 1, wherein two parallel projecting pins are provided as bifurcated protrusions on the side surface of the inertial disk. 3. An inertial delay device for a circuit breaker according to claim 1 or 2, wherein the inertial disc and the bifurcated protrusion are integrally formed of a resin material filled with a non-magnetic metal.