JP3246560B2 - Circuit breaker trip mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tripping mechanism for a circuit breaker such as a circuit breaker or an earth leakage breaker.

[0002]

2. Description of the Related Art In the above-mentioned circuit breaker, the switching mechanism is locked by a trip mechanism, and when an overcurrent condition occurs or a circuit voltage drops, the trip crossbar of the trip mechanism is used. In general, a structure is employed in which a locking operation of an opening / closing mechanism is unlocked by applying a tripping operation force to a movable contact. In this case, the opening / closing mechanism is held in the set state by latching the latch with the latch receiver of the tripping mechanism, and the latch receiver is supported from behind by a claw to receive the force from the latch receiver, but the claw is small. The circuit breaker is fixed to the trip crossbar, whereas the large circuit breaker is generally configured as a lever that applies a force from a latch receiver to the trip crossbar by reducing the force from the lever ratio. It should be noted that any force acting via the pawl is set so as to pass through the center of rotation of the trip crossbar, and care is taken so that almost no power is applied to the trip crossbar.

FIG. 8 is a side view showing the general structure of a tripping mechanism of this type in a conventional circuit breaker. In the figure, 1 is a latch, 2 is a latch receiver, 3 is a pawl, and 4 is a trip crossbar. When the circuit breaker is in the ON state, the latch 1 is about to rotate counterclockwise about a shaft (not shown) by the force of an opening / closing spring (not shown). Have been. On the other hand, the latch receiving 2 is trying to rotate in the clockwise about the shaft 5 as a fulcrum by a force F ₁ from the latch 1, arm 2a integrally extending to the lower right of the figure is supported via the pin 6 to the pawl 3 The roller 7 is locked by the roller 7 and is prevented from rotating.

[0004] pawl 3 also is trying to rotate in the clockwise about the shaft 8 as a fulcrum by the force F ₂ from the latch receiver 2,
An arm 3a extending upward integrally is locked by a catch 9 fixed to the trip crossbar 4 to prevent rotation.
Here, the force F ₃ acting horizontally in the right direction in FIG relative received payments 9 from the arm 3a is fulcrum shaft of the trip cross bar 4 10
It is set to pass through the center. Under such a force relationship, the force F ₁ from the latch ₁ is dropped by the lever ratio L ₁ / L ₂ of the latch receiver 2 and transmitted to the pawl 3 (F ₂ = F _2).
1 · L ₁ / L ₂ <F ₁ ) and the force F from the latch receiver 2
₂ is set as another paragraph by the lever ratio L ₃ / L ₄ of the pawl 3 and transmitted to the trip crossbar 4 (F ₃ = F ₂ · L
_{3 / L 4 <F 2)} .

Since the force F ₃ acting on the trip cross bar 4 is dropped in two steps as described above, the force F ₁ from the latch 1 is applied.
In this case, the trip crossbar 4 passes through the center of rotation of the trip crossbar 4, as described above, so that almost no power is applied to the trip crossbar 4 in any direction, and the illustrated state is maintained. . A return spring 11 urges the latch receiver 2 counterclockwise, a return spring 12 urges the pawl 3 counterclockwise, and a return spring 13 urges the trip crossbar 4 clockwise. .

When an overcurrent state occurs in the ON state of FIG. 8, for example, an overcurrent trip device (not shown) hits the trip crossbar 4 to rotate it in a counterclockwise direction.
As a result, the pawl 3 is unlocked by the catch 9 and pivots clockwise, and accordingly, the latch receiver 2 is unlocked by the roller 7 and pivots clockwise. As a result, the latch 1 is released from latching by the latch receiver 2 and jumps up in the counterclockwise direction to open the movable contact by the opening / closing mechanism (trip operation).

[0007]

In the case of a large circuit breaker, the opening / closing spring becomes strong and the force from the latch 1 increases, so that the force acting on the trip crossbar 4 is excessive if the latch receiver 2 is used as a single stage. Becomes If this force is excessive, a large operating force is required to rotate the trip crossbar 4 against the frictional force acting on the receiving metal 9, which causes a problem that the overcurrent tripping device becomes large. Therefore, as shown in the figure, the pawl 3 is provided to reduce the force to another level, and the force acting on the trip crossbar 4 is made appropriate.

However, in the illustrated configuration in which the claws 3 are interposed between the latch receiver 2 and the trip crossbar 4, the required space for the tripping mechanism is inevitably increased, and the external dimensions of the circuit breaker are correspondingly increased. There was a problem. SUMMARY OF THE INVENTION An object of the present invention is to provide a circuit breaker trip mechanism in which a required space is reduced by devising a component arrangement.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a latch receiver, a pawl, and a trip crossbar which are arranged so that their rotation axes are sequentially located on opposite sides of each other. , The rotation axis of the latch receiver, the latch locking portion of the latch receiver, and
The engaging portion with the claw receiving said latch pivot axis of the pawl, and the engagement portion of the front <br/> Symbol trip crossbar of the engaging portion and the pawl and receiving said latch of said pawl The rotating shaft of the trip crossbar, the engaging portion of the trip crossbar with the claw, and the receiving portion of the trip crossbar for receiving the tripping operation force are arranged in reverse order to each other and substantially parallel to each other. Shall be used.

[0010]

In the conventional construction, the reason why the outer shape of the trip mechanism is increased is that the fulcrum shaft 8 of the claw 3 is provided on the same side as the fulcrum shaft 5 of the latch receiver 2 and the roller 7 of the claw 3 is provided below and below the latch receiver 2. This is because the engagement with the extended arm 2a requires a large space between the latch receiver 2 and the trip crossbar 4 and below them. Therefore, the rotation axis of the latch receiver and the claw are positioned on the opposite sides of each other.
In the same way as above,
Shaft, latch engagement part, and engagement part with the pawl
, The rotation axis of the pawl, the engagement portion with the latch receiver, and the
The order of engagement with the cross bar is opposite to each other
And are arranged substantially in parallel. Accordingly, first, the engaging portion of the pawl with the latch receiver is directly engaged with the opposite side of the latch receiving portion of the latch receiver, so that the extension of the arm from the latch receiver becomes unnecessary, and the dimension in the front-rear direction can be reduced. Can
You . In addition, the pivot axis of the pawl is disposed in the dead space above the latch receiver, so that the pawl does not protrude downward, so that the vertical dimension can be reduced. For similar reasons, nails and
The lip crossbar and their rotation axes are upside down
Side by side, staggered back and forth
The rotation axis of the pawl, the engagement portion with the latch receiver, and the
Between the cross bar and the trip cross bar.
From the rotating shaft, the engaging portion with the claw, and the overcurrent trip device.
The receiving parts of the tripping operation force are in reverse order to each other,
And be arranged substantially in parallel.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Here, FIG. 1 is a side view of the tripping mechanism in the ON state of the circuit breaker, FIG. 2 is a rear view thereof, FIG. 3 is a rear view of the latch receiver in FIG. 1, and FIG. 4 is a rear view of the trip crossbar in FIG. Figure 5, Figure 5 is a side view of the trip mechanism of Figure 1 at the moment the circuit breaker trips, Figure 6 is a side view of the trip mechanism of Figure 1, with the circuit breaker tripped,
FIG. 7 is a vertical sectional view of the circuit breaker having the tripping mechanism of FIG. 1 in an ON state. Note that the same reference numerals are used for the portions corresponding to the conventional example.

First, in FIG. 7, a current flows from a fixed contact 14 integrated with a power supply terminal to a load terminal 18 via a movable contact 15, a lead wire 16, and a heater conductor 17 of an overcurrent trip device. The movable contact 15 is held by an insulating holder 20 rotatably supported by a case 19, and a toggle link 23 is provided between the holder 1 and the latch 1 supported by a shaft 22 on a side plate 21. ing. The toggle link 23 presses the movable contact 15 against the fixed contact 14 by receiving the spring force of an opening / closing spring 25 mounted between the toggle link 23 and a handle lever 24 swingably supported by the side plate 21.

When an overload current continues to flow through the heater conductor 17 in the state shown in the figure, the bimetal 26 is heated and bent to the left in the figure, causing the trip crossbar 4 to rotate counterclockwise. When a short-circuit current flows through the heater conductor 17,
The armature 27 is instantaneously attracted to the fixed magnet 28 to rotate the trip crossbar 4 similarly. Due to the rotation of the trip crossbar 4, the engagement between the trip crossbar 4 and the pawl 3 and the engagement between the pawl 3 and the latch receiver 2 are sequentially released, and the latch 1 is released from the latch receiver 2. Rotates counterclockwise. Thereby, the opening / closing spring 2
5, the toggle link 23 collapses, and the movable contact 15 is rapidly driven clockwise through the holder 20 to open the contact.

FIGS. 1 and 2 are enlarged views of the tripping mechanism in FIG. The latch receiver 2 is rotatably supported by the side plate 21 (FIG. 7) by the shaft 5 and locks the latch 1. Rotation axis 5 of latch receiver 2 and up and down
Side play due to the shafts 8 located on the opposite upper side
The pawl 3 rotatably supported by the port 21
It is arranged alternately behind it and supported by pins 6.
The latch receiver 2 is moved by the latch 7 via the held roller 7.
Locked above the stop. The claw 3 has an arm 3a extending substantially vertically downward, and the tip of the arm 3a is engaged with the receiving metal 9 of the trip crossbar 4 to prevent rotation. one
On the other hand, the trip crossbar 4 is vertically
And rotatably supported by the shaft 10 located on the opposite side
And a catch 9 fixed above the rotating shaft 10
3 is locked. This trip crossbar 4
The overcurrent trip device is tripped by the arm 4a extending further above the gold 9.
Receive the removal operation force. In the arrangement described above, the latch
The pivot shaft 5 and the latching portion (below the locking plate 2b)
(An end face) and an engaging portion with the claw 3 (the back surface of the locking plate 2b);
3 and the engaging portion (low) of the rotation shaft 8 and the latch receiver 2
(A) Engagement portion with 7 and trip crossbar 4 (of arm 3a)
Tip) and the rotation axis 1 of the trip crossbar 4
0, engaging portion (receptacle) 9 with the pawl and receiving the tripping operation force
The parts (arms) 4a are in reverse order to each other, and
They are almost parallel.

As shown in FIG. 3, the latch receiver 2 is formed by bending side plates 2c through which the shaft 5 penetrates on both sides of the locking plate 2b, and has a rectangular window hole 29 in the center of the locking plate 2b. The latch 1 is engaged with the lower end surface of the locking plate 2b, and the roller 7 is engaged with the upper edge of the window hole 29 on the back surface of the locking plate 2b. The claw 3 is formed by bending a side plate 3b through which a shaft 8 penetrates on both sides of an arm 3a. As described above, a roller 7 is supported by a pin 6 at an appropriate distance from the shaft 8 inside the side plate 3b. Have been. Trip crossbar 4
Are insulating bars 4 extending over each phase as shown in FIG.
b, an arm 4a is formed integrally with the overcurrent tripping device of each phase, and a receiving metal 9 made of a letter-shaped plate is fixed at the center by embedding. It is supported by.

In the ON state of the circuit breaker shown in FIG. 1, when the trip crossbar 4 is turned counterclockwise by the operation force of the overcurrent tripping device on the arm 4a, the arm 3a is disengaged with the catch 9 by the arm 3a. The roller 7 falls into the recess 30 of the insulating bar 4b and rotates counterclockwise, and at the same time, the roller 7 comes off the locking plate 2a and falls into the window hole 29. Thereby, the latch receiver 2
Pivots clockwise, then the latch 1 is unlocked and pivots counterclockwise to open the movable contact 15 (FIG. 2).

FIG. 5 shows the instant of such a trip operation. In the state shown in FIG. 5, since the arm 4a in the center phase of the trip cross bar 4 interferes with the side plate 3b of the claw 3, the arm 4a is provided with a recess 31 for escaping the side plate 3b as shown in FIG. . When the current is interrupted and the operating force on the trip crossbar 4 disappears, the pawl 3 and the trip crossbar 4 rise by the action of a return spring (not shown) and engage with each other again as shown in FIG. afterwards,
When the operating handle 32 of FIG. 2 is manually operated clockwise to push the latch 1 against the latch receiver 2, the latch 1 is engaged with the latch receiver 2 again and returns to the state of FIG. 1 (reset operation).

The force relationship in FIG. 1 is the same as in the prior art, and the force F ₁ from the latch ₁ is
₁ / L ₂ and transmitted to the nail 3 (F ₂ = F ₁
・ L ₁ / L ₂ <F ₁ ) and the force F ₂ from the latch receiver ₂
Is made into another paragraph by the lever ratio L ₃ / L ₄ of the pawl 3 and transmitted to the trip crossbar 4 (F ₃ = F ₂ · L ₃
/ L ₄ <F ₂ ). Force F ₃ exerted by the pawl 3 to the trip cross bar 4 passes through the center of the shaft 10, is not applied little rotational force to the trip cross bar 4.

Comparing the embodiment shown in FIG. 1 with the conventional example shown in FIG. 8, in the embodiment, the latch receiver 2, the pawl 3, and the trip crossbar 4 are rotated by their rotating shafts 5, 8, and 10 in order. The rollers 7 are engaged with the latch 1 because the engaging portions are arranged in a reverse order to each other and substantially parallel to each other so as to be located on opposite sides and are alternately arranged back and forth. The arm 2a can be directly engaged with the back surface of the locking plate 2b to be stopped, and the arm 2a as in the conventional example is not required. The shaft 8 of the pawl 3 is located in the dead space above and behind the latch receiver 2.
The arm 3a, which is located at substantially the same height as the upper end of the latch receiver 2 and engages with the trip crossbar 4, extends substantially vertically downward within the height of the latch receiver 2 or the trip crossbar 4. Therefore, the claw 3 does not protrude below the latch receiver 2 or the trip cross bar 4 unlike the conventional example, and the vertical dimension is reduced.

[0020]

As described above, according to the present invention, the latch receiver, the pawl, and the trip crossbar are alternately stacked.
The trip mechanism can be made compact even if a lever-shaped claw is interposed between the latch receiver and the trip crossbar, and the external dimensions of the large circuit breaker are reduced accordingly. can do.

[Brief description of the drawings]

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

FIG. 2 is a rear view of FIG.

FIG. 3 is a rear view of the latch receiver in FIG. 1;

FIG. 4 is a rear view of the trip crossbar in FIG. 1;

FIG. 5 is a side view showing an instant of a trip operation of the tripping mechanism of FIG. 1;

FIG. 6 is a side view showing a trip state of the tripping mechanism of FIG. 1;

FIG. 7 is a longitudinal sectional view of a circuit breaker provided with the tripping mechanism of FIG. 1;

FIG. 8 is a side view of a conventional example.

[Explanation of symbols]

 1 Latch 2 Latch receiver 3 Claw 4 Trip crossbar

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01H 71/12 H01H 83/02

Claims (1)

(57) [Claims] A first latch for locking a latch of an opening / closing mechanism; a trip crossbar for rotating by a tripping force; and a trip crossbar interposed between the trip crossbar and the latch receiver. A tripping mechanism for a circuit breaker, comprising: a rotatable claw that acts on a center of rotation of the trip crossbar by reducing a force received from the latch receiver according to a lever ratio. sequential their rotational axes to each other, so as to be positioned vertically opposite, arranged in staggered overlapped back and forth, the latch receiver of <br/> pivot shaft, said latch receiving the latch engaging portion And the latch
The engaging portion with the claw receiving, the rotation shaft of the pawl, and the engagement portion of said trip cross bar of the engaging portion and the pawl and receiving <br/> the latch of the claw, the trip crossbar rotation shaft, the engaging portion and the front of said claws of said trip cross bar
A trip mechanism for a circuit breaker , wherein the trip crossbar and the receiving portion of the trip operation force are arranged in a reverse order to each other and substantially in parallel with each other.