JP2604702Y2 - Circuit breaker - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker, and more particularly to a structure for holding a movable contact of a circuit breaker or a leakage breaker.

[0002]

2. Description of the Related Art Generally, a circuit breaker has a trip function for automatically shutting off a circuit in order to protect the circuit from an accidental current such as an overcurrent, in addition to a function for opening and closing the circuit.

FIG. 1 is a side sectional view of a center pole showing a conventional three-pole type circuit breaker 101 in a closed state. Circuit breaker 1
Reference numeral 01 denotes a main circuit conductive section, an opening / closing mechanism section, and a trip mechanism section 121 inside the insulating molded base 102 and the cover 103.
Etc. are stored.

[0004] The main circuit conductive portion includes a fixed contact 105 having a power supply side terminal 104, a fixed contact 106 joined to the fixed contact 105, a movable contact 107 detachable from the fixed contact 106, and a movable contact at one end. A movable contact 109 having a contact 107 joined and one end of a flexible conductor 108 joined to the other end.
, A flexible conductor 108, a trip element 110 for operating a trip mechanism 121, and a load terminal 112. The trip mechanism 121 and the trip element 1
Detailed description of 10 is omitted.

The opening / closing mechanism includes a crossbar 114 having one end 114a pivotally supported by a fixed member (not shown).
A movable contact shaft 115 for rotatably supporting the movable contact 109 on the crossbar 114;
A contact pressure spring 116 for biasing the movable contact 109 in a direction in which the movable contact 109 comes into contact with the fixed contact 106, a handle 118 rotatably supported on a fixed shaft (not shown), and an operation spring 127 for providing a throwing force and a breaking force. Although not described in detail, it comprises a mechanism including a link mechanism 120 for connecting the handle 118 and a through hole 114b formed at the other end of the center pole portion of the crossbar 114.

[0006] The circuit breaker 101 thus configured
In the state of FIG. 1, the movable contact 107 is
The fixed contact 106 is in contact with the fixed contact 106 by the spring force of No. 6 and is in a closed state. From this closed state shown in FIG.
When the is rotated in the counterclockwise direction, the opening / closing mechanism operates, and the crossbar 114 receives an acting force in the through hole 114b, and moves counterclockwise together with the movable contact 109 around one end 114a of the crossbar 114. Rotating, the movable contact 107 is separated from the fixed contact 106, so that the circuit breaker 101 is opened. The closing operation is the reverse of the opening operation.

Since the crossbar 114 is common to the movable contacts for three poles, FIG. 2 shows the movable contact 109 of the conventional circuit breaker 101 as described above.
2 shows a state in which two poles are attached first, and the other pole is in a state before attachment, and FIG. 3 is a side sectional view taken along AA in FIG. In FIGS. 2 and 3, the movable contact 109 is connected to the opposite wall 114 of the crossbar 114.
a, 114a, are rotatably supported by the movable contact shaft 115 inserted through the through holes 114c, 114c. The contact pressure spring 116 moves the movable contact 10 around the movable contact shaft 115.
9 is a double torsion type torsion spring wound on both sides. One end 116a of such a contact pressure spring 116 is engaged with the crossbar 114, and the other end 116b is
9, the movable contact 109 is displaced clockwise, and the movable contact 109 is
In contact with the stopper 114d formed at the stop position.

[0008]

In order to attach the movable contact 109 of such a conventional circuit breaker 101 to the crossbar 114, first, as shown in FIG.
09 and the contact pressure spring 116 as a set, and are inserted in the direction of the arrow to hold the set of the movable contact 109 and the contact pressure spring 116 at a predetermined position.
The movable contact shaft 115 must be passed through the through holes 114c, 114c in the direction of the arrow with respect to the set of the contact pressure spring 116 and the contact spring 116. In such an assembly process, the movable contact 10
The set 9 and the pressure spring 116 must be held in a place without a guide and against the spring force of the pressure spring 116.

The spring force of the contact pressure spring 116 obtains the contact pressure between the fixed contact 106 and the movable contact 107 in order to safely supply a current to the main circuit conductive portion, and is not small. Until the shaft 115 is inserted into the through holes 114c, 114c, the movable contact 109 and the contact pressure spring 1 are manually inserted.
It was difficult to hold 16 sets in place. Therefore, conventionally, a set of the movable contact 109 and the contact pressure spring 116 is attached by using a jig, but problems such as poor workability and reduced productivity are found.

Accordingly, an object of the present invention is to provide a circuit breaker in which the movable contact can be easily attached to the crossbar without any jig in order to solve such a conventional problem. Is to do.

[0011]

According to the present invention, a circuit breaker includes a fixed contact, a movable contact which rotates and comes into contact with and separates from the fixed contact, and a movable contact which extends in the longitudinal direction. A contact pressure comprising a movable contact shaft that is supported at one end of the movable contact, a crossbar that is supported by a fixed member and holds the movable contact shaft, an opening and closing operation mechanism that rotates the crossbar together with the movable contact, and a torsion spring A spring, wherein the contact pressure spring includes a wound portion formed around the movable contact axis on both sides of the movable contact, and a connecting portion connecting one end of the wound portions to each other; A leg formed at the other end of both winding portions, wherein the connecting portion is engaged with the movable contact, the leg is engaged with the crossbar, and the movable contact is fixedly contacted. So that it is biased in the direction of contact with the In the circuit breaker, the ends of the legs of the contact pressure spring are bent and formed so as to be folded, and the movable contact is provided on the crossbar and formed along the longitudinal direction of the movable contact. A movable contact shaft extending downward from the upper end thereof to a predetermined position is disposed between the opposing walls of the substantially U-shaped wall, the cross sections of which are not connected to each other. A groove to be fitted is formed, and the crossbar is further provided that the movable contactor, the contact pressure spring, and the movable contactor shaft are temporarily assembled and the movable contactor shaft is moved along the groove. A sliding wall formed substantially in parallel with the groove in which the leg slides while receiving the biasing force of the contact pressure spring, a leg engaging portion of the contact pressure spring with the leg, and a The contact pressure spring having a folded portion and a foldable engagement portion engageable. An opening formed in a portion such that the movable contact shaft is pressed against the lower end of the groove by the biasing force of the contact pressure spring when in engagement with the leg engaging portion. It is characterized by.

[0012]

According to the present invention, the movable contact can be easily attached to the crossbar. That is, first, the portion of the crossbar that holds the movable contact is a U-shaped wall, and since the upper portion thereof is not connected, the movable contact can be attached from above, thereby facilitating the attachment. Furthermore, while temporarily assembling the movable contact, the movable contact shaft and the contact pressure spring, and pressing the leg of the contact pressure spring against the sliding wall, the movable contact shaft is fitted into the upper end of the groove starting from the upper end of the wall,
By simply pressing the movable contact downward, the movable contact shaft moves along the groove, and the leg of the contact pressure spring also moves along the sliding wall. When the leg portion of the contact pressure spring separates from the sliding wall and engages with the opening of the cross bar, the movable contact shaft is pressed against the lower end of the groove by the biasing force of the contact pressure spring, and the position as the rotation shaft is established. By simply moving the movable contact from above so as to determine the position, the effect of the biasing force of the contact pressure spring can be minimized and the contact can be easily mounted.

Further, since the ends of the leg portions of the contact pressure spring are bent so as to be folded, and the opening of the crossbar is formed so as to be able to engage with the folded portion, the crossbar is subjected to a large current such as a short-circuit current. Even if the movable contact is lifted by the electromagnetic force, that is, even if the movable contact shaft is urged to move upward, the folded portion engages with the periphery of the opening so that the movable contact shaft is at the upper end of the groove. Never get out of the way.

[0014] Other objects, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0015]

4 to 8 show an embodiment of a three-pole type circuit breaker according to the present invention. FIG. 4 is a side sectional view showing a closed state of the three-pole type circuit breaker 1 of the present invention. FIG. The circuit breaker 1 is configured such that a main circuit conductive portion, an opening / closing mechanism portion, a trip mechanism portion, and the like are housed inside a base 2 and a cover 3 made of an insulating molded product. Such a configuration will be described below.

The main circuit conductive part includes a fixed contact 5 having a power supply terminal 4 and a fixed contact 6 joined to the fixed contact 5.
A movable contact 7 having one end to which the movable contact 7 is joined and the other end joined to one end of a flexible lead 8; And heater 10
And a flexible lead 13 connecting the other end of the heater 10 and the load-side terminal 12.

The opening / closing mechanism includes a crossbar 14 rotatably supported by a fixed member (not shown), a movable contact shaft 15 rotatably supporting the movable contact 9 on the crossbar 14, A contact pressure spring 16 for biasing the movable contact 9 in a direction in which the contact 7 contacts the fixed contact 6, a handle 18 rotatably supported on a fixed shaft 17, and one end of the fixed shaft 1
The trip lever 2 is rotatably supported by the pivot 9 and the other end is freely engageable with the pawl 20 operated by the trip mechanism.
1, a first link 23 having one end rotatably and eccentrically connected to the crossbar 14 at a first connection point 22, and a second connection between the other end of the first link 23 and the trip lever 21. A second link 26 is rotatably connected at a point 24 and a third connection point 25, and an operation spring 27 is provided between the handle 18 and the second connection point 24.

The tripping mechanism includes a trip shaft 29 rotatably supported by a fixed member and a trip shaft 2.
9, a trip shaft return spring 31 for biasing the trip shaft 29 in a direction in which the pawl 20 engages the trip lever 21.
A bimetal 32 provided in parallel with the heater 10, one end of which is fixed and the other end of which is provided with a bimetal adjustment screw 35 facing the trip piece 30, and a cross section provided so as to surround the heater 10 has a U-shape. One end faces the U-shaped leg of the fixed core 33 made of a magnetic material and the U-shaped leg of the fixed core 33, and the other end faces the trip piece 30. The fixing member (not shown) is rotatable at an intermediate portion 33a. And a movable core 34 made of a magnetic material and supported by the shaft.

The operation of the circuit breaker 1 thus constructed according to the present invention will be described below. In the closed state shown in FIG. 4, first, the horizontal component of the spring force of the operation spring 27 biases the second connection point 24 rightward, so that the second connection point 24 abuts on a fixing member (not shown), The first, second and third connection points 22, 24 and 25 are almost straight and stopped. At this time, the movable contact 7 is in contact with the fixed contact 6 by the spring force of the contact pressure spring 16.

When the handle 18 is turned counterclockwise from such a closed state, an opening operation can be performed. The handle 18 rotates counterclockwise, and the operation spring 27 rotates counterclockwise about the second connection point 24, and the operation spring 2 rotates.
When the action line 7 goes beyond the third connection point 25, the second connection point 2
4 rotates clockwise around the third connection point 25 by the spring force of the operation spring 27. As a result, the crossbar 14 rotates counterclockwise with the movable contact 9 via the first link 23, so that the fixed contact 6 and the movable contact 7 are separated from each other, and the circuit is opened. At this time, handle 18
Stops in contact with a fixing member (not shown). The closing operation is the reverse of the opening operation.

Next, the operation when an overcurrent flows in the conductive portion of the main circuit in the closed state of FIG. 4 will be described. When the overcurrent is small, the heater 10 generates heat due to Joule heat, and the juxtaposed bimetal 32 is heated and slowly bent to the right, and the bimetal adjusting screw 35 comes into contact with the trip piece 30 in due course. When the overcurrent is large, one end of the movable core 34 is instantaneously attracted to the fixed core 33 by the magnetic force and rotates clockwise, and the other end of the movable core 34 contacts the trip piece 30. In any case, the trip shaft 29 can be rotated counterclockwise.

When the trip shaft 29 rotates counterclockwise in this manner, the engagement between the claw 20 and the trip lever 21 is released, and the trip lever 21 is rotated clockwise about the fixed shaft 19 by the spring force of the operation spring 27. To rotate. As a result, the third connection point 25 moves to the right of the action line of the operation spring 18 and the second connection point 24 moves to the third connection point 2.
Move upward while rotating clockwise around 5,
The cross bar 14 is connected to the movable contact 9 via the first link 23.
Together with the fixed contact 6 and the movable contact 7
Is opened, the circuit breaker is opened. At this time, the trip lever 21 comes into contact with a fixing member (not shown) and stops, and the handle 18 stops at a trip position intermediate between the open position and the closed position.

In order to change from such a trip state to a closed state, the handle 18 is once rotated counterclockwise to engage the pawl 20 and the trip lever 21 to reset the circuit to an open state. After that, the handle 18 is rotated clockwise.

In this embodiment shown, the crossbar 1
4 has opposing walls 14a, 14a connected to the lower part of the movable contact 9 for each pole.
Grooves 14b, 14b are respectively formed in 14a so as to face each other. One end 14c of each groove 14b is open without a wall, and the other end 14d is formed with a wall. Two through holes 14e, 14e are formed in a wall 14f orthogonal to the walls 14a, 14a. Further, a hole is formed in the movable contact 9 and the movable contact shaft 15 is inserted therethrough. A contact pressure spring 16 composed of a double torsion type torsion spring is provided around the movable contact shaft 15 on both sides of the movable contact 9. The central portion 16c of the contact pressure spring 16 is engaged with the movable contact 9, and both end portions 16a, 16a of the contact pressure spring 16 are formed in a “V” shape, and the through-holes 14e of the cross bar 14 are formed. 14e.

The spring force of the contact pressure spring 16 attached to the cross bar 14 in this manner crosses the wall 14f forming the through hole 14e at the end 16a and the movable contact shaft 15 at the winding portion 16b. The contact pressure spring 16 acts to press against the wall 14d at the other end of the groove 14b of the bar 14.
The central contact 16c acts to rotate the movable contact 9 clockwise. In FIG. 6, the movable contact 9 contacts the stopper 14g of the crossbar 14 and moves.
Is stopped.

The movable contact 9 according to the embodiment of the present invention as described above.
As a method for attaching the movable contact 9 to the cross bar 14, first, as shown in FIG. 7, the movable contact 9, the movable contact shaft 15 and the contact pressure spring 16 are temporarily assembled in advance, and then, as shown in FIG. The end 16a of the pressure spring 16 is moved downward by sliding on the wall 14f of the cross bar 14 against the acting force of the contact pressure spring 16, and the movable contact shaft 15 is fitted into one end 14c of the groove 14b. There is a method of moving the movable contact 9 downward along the groove 14b until the end 16a of the contact pressure spring 16 is inserted into the through hole 14e.

Furthermore, as another mounting method, first, FIG.
As described above, the central portion 16c of the contact pressure spring 16 is temporarily assembled without engaging the predetermined portion of the movable contact 9, and the movable contact shaft 15
The temporary assembly is moved so that the end 16a of the contact pressure spring 16 is at a predetermined position, and then the central portion 16c of the contact pressure spring 16 is moved to the predetermined position of the movable contact 9 against the spring force. When the temporary assembly is moved, no spring force is applied. When the contact pressure spring 16 is engaged with a predetermined position of the movable contact 9, the movable contact shaft 15 Since they remain at the predetermined positions, they can be easily engaged with an extremely simple tool.

In either method, the temporarily assembled product can be attached to a predetermined position only by slightly moving the temporarily assembled product from the upper portion of the crossbar 14 and by a predetermined movement. When the spring force is applied, since the movable contact shaft 15 is engaged with the groove 14b, the spring force does not hinder the mounting.

Since the end 16a of the contact pressure spring 16 of the circuit breaker according to the embodiment of the present invention is formed in a "V" shape, when a large current such as a short-circuit current flows in FIG.
The fixed contact 6 and the movable contact 7 try to be separated by the electromagnetic repulsion, and the other end 9a of the movable contact 9 and the flexible lead 8
The other end 9a is lifted upward because currents flow in different directions from each other, that is, the movable contact shaft 15 is
4b acts by the electromagnetic repulsive force, and if the end of the contact pressure spring 50 is linear, the engagement with the wall 14f of the crossbar 14 is prevented as shown in FIG. Although it may come off, in the embodiment of the present invention, the contact pressure spring 16
The "V" -shaped end of the end 16a does not engage with the outer wall of the wall 14f of the crossbar 14 and does not come off.

[0030]

As is apparent from the above description, according to the present invention, the movable contact 9, the movable contact shaft 15 and the contact pressure spring 16 are temporarily assembled to move the movable contact 9 in its longitudinal direction. The movable contact shaft 1 can be moved slightly straight
5 can be engaged with the groove 14b of the crossbar 14, and assembly can be performed only by moving along the groove 14b to a predetermined position, so that the work is simple and the productivity of assembly is increased.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a prior art circuit breaker.

FIG. 2 is a plan view showing a state where a movable contact of the circuit breaker of the prior art of FIG. 1 is assembled to a crossbar.

FIG. 3 is a side sectional view taken along line AA of FIG. 2;

FIG. 4 is a side sectional view of the circuit breaker of one embodiment according to the present invention.

FIG. 5 is a plan view showing a state where the movable contact of the circuit breaker of FIG. 4 is assembled to a crossbar.

FIG. 6 is a side sectional view taken along line BB of FIG. 5;

FIG. 7 is a side sectional view showing a method of assembling the movable contact of the circuit breaker of FIG. 5 into a crossbar.

FIG. 8 is a similar view showing a state in the middle of the assembling method in FIG. 7;

FIG. 9 is a side sectional view showing another method of assembling the movable contact of the circuit breaker into a crossbar.

FIG. 10 is a diagram illustrating that inconvenience occurs due to a short-circuit current when the end of the contact pressure spring is not bent.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Circuit breaker 2 Base 3 Cover 4 Power supply side terminal 5 Fixed contact 6 Fixed contact 7 Movable contact 8 Flexible lead 9 Movable contact 10 Heater 11 Relay terminal 12 Load side terminal 13 Flexible lead 14 Cross bar 15 Movable contact Shaft 16 Contact pressure spring 17 Fixed shaft 18 Handle 19 Fixed shaft 20 Claw 21 Trip lever 22 First connection point 23 First link 24 Second connection point 25 Third connection point 26 Second link 27 Operation spring 29 Trip shaft 30 Trip piece 31 trip shaft return spring 32 bimetal 33 fixed core 34 movable core 35 bimetal adjustment screw

Claims (1)

(57) [Scope of request for utility model registration] 1. A fixed contact (5), a movable contact (9) that comes into contact with and separates from the fixed contact by rotating, and a movable contact shaft that supports the movable contact at one longitudinal end thereof. (15) a crossbar (14) supported by a fixed member to hold the movable contact shaft, an opening / closing operation mechanism (18) for rotating the crossbar together with the movable contact, and a contact pressure spring comprising a torsion spring (16),
The contact pressure spring includes a winding portion (16b) formed around the movable contact axis on both sides of the movable contact and a connecting portion (16c) connecting one ends of the both winding portions to each other.
And a leg (16a) formed at the other end of the two winding portions, wherein the connecting portion is engaged with the movable contact, and the leg is engaged with the crossbar, and the movable contact is formed. In a circuit breaker configured to bias a contact in a direction in which the contact comes into contact with the fixed contact, an end of a leg of the contact pressure spring is formed to be bent so as to be folded, and the movable contact is formed of the cross. The opposing walls (14a) and (14a) of a U-shaped cross-section wall provided on the bar and having an upper end formed along the longitudinal direction of the movable contact and not connected to each other.
a), a groove (14b) in which a movable contactor shaft extending downward from an upper end thereof to a predetermined position is fitted in the opposing walls, and the crossbar further comprises: When the movable contact, the contact pressure spring and the movable contact shaft are temporarily assembled and the movable contact shaft is moved along the groove, the leg slides while receiving the biasing force of the contact pressure spring. A sliding wall (14f) formed substantially in parallel with the groove, a leg engagement portion with the leg of the contact pressure spring, and a folded engagement portion engageable with the folded portion of the leg; When the contact pressure spring is engaged with the leg engaging portion, the movable contact shaft is caused to move by the biasing force of the contact pressure spring to a lower end of the groove (14d).
Opening (14) formed in a portion pressed against
e).