JP4399102B2 - Circuit breaker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a connection portion in a circuit breaker, for example, in electrical connection between a movable contact mechanism and a connection conductor of an overcurrent trip unit.
[0002]
[Prior art]
FIG. 7 is a front sectional view showing a part of a conventional circuit breaker disclosed in, for example, Japanese Patent Publication No. Sho 62-54226, with a part thereof cut away. FIG. 8 is a front sectional view showing the overcurrent tripping unit housed in the circuit breaker of FIG. FIG. 9 is a front view showing the movable contact portion, and FIG. 10 is a bottom view showing the movable contact portion. FIG. 11 is a side view showing a main part of the circuit breaker of FIG.
In FIG. 7, reference numeral 60 denotes a circuit breaker unit. In the insulation box 61, a power supply side fixed terminal 62, a fixed contact 63 fixed to one end of the power supply side fixed terminal 62, and the fixed contact 63 are opposed to each other. A movable contact 64 that contacts and separates, a movable contact 65 having the movable contact 64 fixed to one end, a connection terminal 66 to which a conductor 72 of an overcurrent tripping unit 70 described later is connected, and the movable contact 65 are provided. A conductive member such as a flexible wire 67 connected to the connection terminal 66 is incorporated so that it can move smoothly.
[0003]
Reference numeral 70 denotes an overcurrent tripping unit mounted on the circuit breaker body corresponding to the selected rating. As shown in FIG. 8, a connection terminal is connected to the conductor 72 fixed in the tripping unit box 71. A terminal connection screw 73 for electrically contacting a contact surface 66a (indicated by a two-dot chain line) of 66 is screwed. Further, as shown in FIGS. 9 and 10, a nut 68 is fixed to the surface 66b of the connection terminal 66 opposite to the contact surface 66a.
[0004]
Next, the structure which improves the contact reliability of the internal connection conductor of the conventional circuit breaker is demonstrated.
As shown in FIGS. 10 and 11, the flexible lead 67 connected to one end of the movable contact 65 includes one contact surface 66 a that cooperates with the connection terminal 66 of each pole, and the opposite surface 66 b includes A nut 68 is fixed. Further, in the lateral slot 61a formed in the insulating box 61 to which the connection terminal 66 of each circuit breaker unit 60 is mounted, the connection terminal 66 is disposed so as to have a vertical play d.
Therefore, when the overcurrent tripping unit 70 is tightened to the nut 68 by the terminal connection screw 73 at the mounting position on the insulating box 61, the overcurrent tripping unit 70 is positioned at a predetermined position on the insulating box 61. The electrical connection between the conductor 72 of the overcurrent tripping unit 70 and the connection terminal 66 is ensured regardless of any defects such as dimensional accuracy errors and burrs on the surface of the connection terminal 66.
[0005]
[Problems to be solved by the invention]
In the structure of the internal connection conductor of the conventional circuit breaker as described above, the movable contact 65 and the conductor 72 of the overcurrent tripping unit 70 are always good even when the movable contact 65 opens and closes. In order to maintain a good electrical contact, the flexible conductor 67 was used. However, since the electrical opening / closing performance is lowered due to the cutting of the flexible conductor 67 due to the opening / closing operation of the circuit breaker, and the flexible conductor 67 cannot be kept in a flexible and constant shape, the position of the various components such as the base 69 can be reduced. The relationship becomes unstable, and the problem of hindering the automation of incorporation into the circuit breaker body is likely to occur. Therefore, by eliminating the flexible member and adopting a sliding contact structure (not shown) using a rigid body, the problem has been solved.
[0006]
However, a sliding contact structure using a rigid body may cause a dimensional error between the disconnecting unit consisting of a movable contact and the connecting conductor of the overcurrent tripping unit due to variations in component parts. There is a problem that the electrical contact between the unit and the overcurrent tripping unit is not stable.
[0007]
The present invention has been made to solve such a problem, and uses a sliding contact member made of a plate material without using a flexible conductive wire, and an interruption unit and an overcurrent tripping unit made of a movable contactor. It is an object of the present invention to provide a circuit breaker that can obtain stable electrical contact with the circuit breaker.
[0008]
[Means for Solving the Problems]
In the circuit breaker according to the present invention, a movable contact disposed opposite to the fixed contact, together with the fixed contact, in the cut-off unit case made of a synthetic resin material provided for each pole, the movable contact A movable element shaft that rotatably supports the child, a cross bar that engages with the movable contact and is connected to an opening / closing mechanism for opening / closing the movable contact, and an overcurrent tripping unit at one end A movable contact mechanism having a connection surface for screwing connection with a connection conductor, the other end being electrically connected to the movable contact by sliding contact with the movable contact; and the like, and In a circuit breaker having a breaker unit configured to hold a rotor shaft of a movable contactor mechanism by a breaker unit case so that the movable contactor can be opened and closed with respect to the fixed contactor, the connection surface of the mover holder Overcurrent trip unit A rail groove in the same direction as the tightening direction is provided in the shutoff unit case with respect to the tightening direction when screwed into the connecting conductor of the robot with a tightening screw, and the mover holder is movably fitted in this rail groove. By doing so, the mover holder moves at the time of the screw connection, and the connection surface comes into contact with the connection conductor of the overcurrent tripping unit.
[0009]
Also, the other end of the mover holder is electrically connected to the movable contact by sliding contact, and a hole through which the mover shaft passes is provided, and the diameter of the hole is drawn to the connecting surface of the mover holder. This is a size that does not restrain the movement of the mover holder when the connecting conductor of the detachment unit is screwed and connected with a tightening screw.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a front sectional view of a circuit breaker showing Embodiment 1 of the present invention. FIG. 2 is a perspective view showing a contact mechanism of the circuit breaker of FIG. FIG. 3 is a plan view of the contact mechanism of FIG. FIG. 4 is a front view of the contact mechanism of FIG. FIG. 5 is a front view showing a blocking unit case in which the contact mechanism of FIG. 2 is incorporated. FIG. 6 is a perspective view showing an overcurrent tripping unit of the circuit breaker of FIG.
[0011]
In the figure, reference numeral 10 denotes a housing, which includes a base 11, a cover 12, and an auxiliary cover 13, all of which are made of a synthetic resin material. Reference numeral 14 denotes a handle made of the same material. Reference numeral 35 denotes a cross bar, which includes a rotor 15 of each pole made of a synthetic resin material and its connecting pin 16. That is, the rotor 15 of each pole is integrally connected by the connecting pin 16. The connecting pin 16 is connected to an opening / closing mechanism 30 described later. Reference numeral 17 denotes a fixed contact, which has a fixed contact 17a. Reference numeral 18 denotes a movable contact, which has a movable contact 18a facing and separating from the fixed contact 17a, and is rotatably supported by a mover shaft 19. The movable contact 18 is configured to engage with the cross bar 35 and be opened and closed by an opening / closing mechanism 30 connected to the cross bar 35.
[0012]
Reference numeral 21 denotes a mover spring by a twist spring. One end of the mover spring is engaged with the outer peripheral portion of the rotor 15, and the other end is engaged with the moveable contactor 18, whereby the movable contactor 18 is urged in the direction of arrow C. . By this urging, the movable contact 18 comes into contact with the fixed contact 17 with a predetermined contact pressure. With this configuration, the movable contact 18 can be rotated in the direction of arrow D against the mover spring 21 regardless of the rotor 15. The movable contact 18 is interlocked with the turning operation of the cross bar 35. That is, when the rotor 15 of the cross bar 35 is rotated by the operation of the opening / closing mechanism 30 described later, the movable contact 18 is driven by the rotation to contact and separate from the fixed contact 17.
[0013]
Reference numeral 20 denotes a mover holder made of a conductive material, which has a connection surface 20b at one end and a pair of connection conductor portions 20a (shown in FIG. 3) at the other end. The connecting conductor portion 20a is formed so as to hold the electrical contact by being pressed by the holder spring 34 with the flat surfaces 18b and 18c on both sides of the movable contactor 18 being sandwiched from both sides. Further, a through hole 20d (shown in FIG. 4) through which the mover shaft 19 passes is provided at the tip of the connection conductor portion 20a. In this configuration, the movable contact mechanism 50 shown in FIGS. 2 to 4 is formed by the rotor 15 of the crossbar 35, the movable contact 18, the mover shaft 19, the mover holder 20, the mover spring 21, the holder spring 34, and the like. It is configured.
Each of these components, that is, the movable contact mechanisms 50 and 17 are fixed contacts, and the arc extinguishing device 24 described later is housed in the interruption unit case 23a. Details of the interruption unit case 23a will be described later.
[0014]
31 is a known overcurrent tripping device, and 22 is a trip bar constituting a part thereof. When the overcurrent tripping device 31 detects an overcurrent, the trip bar 22 rotates counterclockwise about an axis (not shown) as a fulcrum, and the opening / closing mechanism 30 is operated by this rotation. By this operation, the cross bar 35 is rotated, and the movable contact 18 is separated from the fixed contact 17 to automatically shut off (trip). As is well known, the opening / closing mechanism 30 can be operated by the handle 14 so that the movable contact 18 and the fixed contact 17 can be separated and closed.
[0015]
Reference numeral 23 denotes a blocking unit including the fixed contact 17, the movable contact mechanism 50, and the arc extinguishing device 24. That is, as shown in FIG. 1, reference numeral 23 a denotes a blocking unit case made of a synthetic resin material, in which the stationary contact 17, the movable contact mechanism 50, and the arc extinguishing device 24 are housed. At the time of this storage, both ends of the rotor shaft 19 constituting the movable contact mechanism 50 are held by the blocking unit case 23 a so that the movable contact 18 can be opened and closed with respect to the fixed contact 17. .
[0016]
In FIG. 6, reference numeral 40 denotes an overcurrent trip unit configured to be selectively used corresponding to the rated current value of the circuit breaker, and is connected to the connection surface 20b of the mover holder 20 (shown in FIG. 2). A connecting conductor 41 is provided via a relay base 42. The connection conductor 41 is provided with a tightening screw 43 for connection with the connection surface 20b of the mover holder 20.
[0017]
The mover shaft 19 is a rotating shaft of the movable contact 18 and also passes through these parts so as to function also as a rotating shaft of the rotor 15, and a bearing hole 23 b ( (Shown in FIG. 5).
[0018]
As shown in FIG. 3, the connecting conductor portion 20 a formed at the other end of the movable element holder 20 is pressed against both flat surfaces 18 b and 18 c of the movable contact 18 by the holder spring 34, The mover holder 20 is electrically connected by sliding contact. In addition, a through hole 20d through which the mover shaft 19 passes is provided at the distal end portion of the connection conductor portion 20a. This through-hole 20d is not used as a bearing hole for the mover shaft 19, but is used to integrate the movable contact 18 and the mover holder 20 during automatic assembly or the like. Accordingly, the through hole 20d has a hole diameter having a gap G1 with respect to the mover shaft 19, as shown in FIG. This gap G1 suppresses movement of the mover holder 20 when the connection conductor 41 of the overcurrent tripping unit 40 is screwed and connected to the connection surface 20b of the mover holder 20 with the tightening screw 43, as will be described later. It is made to a size that does not. In the above-described embodiment, the through hole 20d is formed as a round hole, but it may be a long hole having a predetermined gap G1 between the through hole 20d. Further, the connecting surface 20b of the mover holder 20 may be shortened so that there is no through hole 20d.
[0019]
As shown in FIG. 1, the mover holder 20 is connected to the connection surface 20b of the mover holder 20 of the interrupting unit 23 and the connection conductor 41 of the overcurrent tripping unit 40 with a tightening screw 43 in the direction of the arrow H, that is, The fastening screw 43 is configured to be movable in the thrust generation direction. That is, a predetermined gap G <b> 1 is provided between the through hole 20 d and the mover shaft 19. Moreover, it is comprised so that the freedom degree equivalent to the predetermined gap G2 may be given between the upper end part of the needle | mover holder 20, and the side wall 23e of the interruption | blocking unit case 23a. Further, as shown in FIG. 5, the blocking unit case 23a is provided with a rail groove 23c, and the vertical piece 20e of the mover holder 20 is movably fitted in the rail groove 23c. Therefore, the mover holder 20 is positioned by the rail groove 23c and is movable in the arrow H direction. As shown in FIG. 5, the interruption unit case 23 a has a nut 45 used when the connection conductor 41 of the overcurrent tripping unit 40 is screwed and connected to the connection surface 20 b of the mover holder 20 with a tightening screw 43. Has a holding hole 23d.
[0020]
Further, the operation by the handle 14 is performed by connecting a well-known toggle link mechanism (opening / closing mechanism 30) and a connecting pin 16 penetrating the rotor 15 of each pole, and moving the movable contact 18 through the rotor 15 (crossbar 35). The electric circuit is opened and closed with the stationary contact 17 by rotating.
[0021]
In the circuit breaker configured as described above, when the movable element holder 20 of the breaking unit 23 and the connection conductor 41 of the overcurrent tripping unit 40 are connected by the tightening screw 43, the movable element holder 20 is tightened by tightening the tightening screw 43. However, since it is configured to be able to move on the rail groove 23c of the interruption unit case 23a in the direction in which the tightening screw 43 generates the thrust, the assembly of the movable element holder 20 of each pole and the connection conductor 41 of the overcurrent trip unit 40 The error can be absorbed and stable electrical contact between the connection conductor 41 and the mover holder 20 can be obtained.
[0022]
【The invention's effect】
According to the circuit breaker of the present invention, when the movable element holder of the breaking unit and the connection conductor of the overcurrent tripping unit are connected by the tightening screw, the movable element holder moves on the rail groove of the breaking unit case by the thrust of the tightening screw. Since it comprised so that it could do, the stable electrical contact with a interruption | blocking unit and a tripping unit can be obtained.
[Brief description of the drawings]
FIG. 1 is a front sectional view showing a circuit breaker of the present invention.
FIG. 2 is a perspective view showing a movable contact mechanism of the circuit breaker of FIG.
FIG. 3 is a plan view of the movable contact mechanism of FIG.
4 is a front view of the movable contact mechanism shown in FIG. 2. FIG.
FIG. 5 is a front view showing a blocking unit case.
FIG. 6 is a perspective view showing an overcurrent tripping unit of a circuit breaker.
FIG. 7 is a front sectional view showing the inside of a conventional circuit breaker.
8 is a front sectional view showing an overcurrent tripping unit of the circuit breaker of FIG.
FIG. 9 is a front view showing a movable contact portion of a conventional circuit breaker.
FIG. 10 is a bottom view showing a movable contact portion of a conventional circuit breaker.
11 is a side view showing a main part of the circuit breaker shown in FIG. 7;
[Explanation of symbols]
14 Handle, 17 Fixed contact, 18 Movable contact, 19 Movable shaft,
20 mover holder, 20a connecting conductor, 20b connecting surface,
20d through hole, 23 blocking unit, 23a blocking unit case,
23c rail groove, 23e side wall, 24 arc extinguishing device, 30 opening / closing mechanism,
35 Crossbar, 40 Overcurrent trip unit, 41 Connecting conductor,
43 Clamping screw, 50 Movable contact mechanism, G1, G2 Predetermined gap.

Claims (2)

In a blocking unit case made of a synthetic resin material provided for each pole, a movable contact disposed opposite to the fixed contact, together with a fixed contact, and the movable contact are supported rotatably. A mover shaft, a crossbar that engages with the movable contact and is connected to an opening / closing mechanism to open and close the movable contact, and a connection conductor of the overcurrent tripping unit at one end and screwed A movable contact mechanism having a connection surface for connection and having the other end electrically connected to the movable contact by sliding contact with the movable contact mechanism; In a circuit breaker having a breaker unit configured such that the rotor shaft is held by the breaker unit case and the movable contact can be opened and closed with respect to the fixed contact, an overcurrent is applied to the connection surface of the mover holder. Connection of trip unit A rail groove in the same direction as the tightening direction with respect to the tightening direction when screwing and connecting to the conductor with a tightening screw is provided in the interruption unit case, and the mover holder is movably fitted in the rail groove. The circuit breaker is characterized in that the mover holder moves during the screw connection, and its connection surface comes into contact with the connection conductor of the overcurrent tripping unit. The other end of the mover holder is electrically connected to the mover contact by sliding contact, and a through-hole through which the mover shaft passes is provided. 2. The circuit breaker according to claim 1, wherein the circuit breaker is sized so as not to suppress movement of the mover holder when the connecting conductor of the unit is screwed and connected with a tightening screw.

Images