JPH0218902Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a neutral pole switching device for a single-phase three-wire or three-phase four-wire low-voltage circuit such as a distribution board.

``Prior Art'' Generally, in the internal structure of a distribution board, etc., a branch conductor is led out from a main switch, and one of the branch conductors is used as a neutral bus (ground conductor). Therefore, it is necessary to measure the insulation resistance inside the distribution board, such as between branch switches, between conductive parts and metal casings, etc., and when doing so, the current feeding to the neutral bus must be cut off. , a neutral pole switching device is required to cut off the current feed. That is, the neutral pole switch is turned on during normal use, and turned off during insulation measurement.

``Problems to be solved by the invention'' By the way, conventional neutral pole switching devices have a structure that turns off when the spring is energized and turns on when the spring is de-energized.In order to turn on and connect when the spring is de-energized, Even if the compressed length is short, sufficient pressing force must be applied, and increasing the spring may damage the case or make the case thicker than necessary. Also, the spring force is strong and the lever operation itself is heavy. Furthermore, the molded circuit breaker is turned on when the spring is energized and turned off when the spring is deenergized, and the neutral pole switching device is operated in the opposite manner, which can be confusing and lead to erroneous operation.

``Means to solve the problem'' This invention turns on when the spring is applied and turns off when the spring is deenergized, making the operation the same as that of a molded circuit breaker. In order to use a lowering type lever and to further miniaturize this opening/closing device as much as possible, an upper accommodation chamber and a lower accommodation chamber are provided in the insulating case, and the upper accommodation chamber and the lower accommodation chamber are communicated with each other by a guide groove. A mounting groove is formed below the lower storage chamber, and a lever whose lower end surface is formed as a cam surface is placed in the upper storage chamber, and the cam surface is in contact with the lower wall of the lever, and the cam surface is in contact with the lower wall of the upper storage chamber, and the lever is inserted into the vertical guide elongated hole carved in the vertical wall. The connecting plate is housed so as to be rotatable around a support shaft with an end located at the center thereof, and the upper end of the connecting plate having a catch piece protruding from the center is pivoted to the support shaft, and a movable contact piece is arranged below the connecting plate. A coil spring is fitted and compressed between the movable contact piece and a seat plate provided at the lower end of the connecting plate to bias the movable contact piece, and the upper part of the connecting plate
A movable contact piece part and a coil spring part are housed in the guide groove, the lower storage chamber, and the mounting groove, respectively, and a return coil spring is fitted and compressed onto a connecting plate between the engagement step part formed in the guide groove and the seat piece, A neutral electrode opening/closing device is constructed by arranging a lead terminal and a neutral electrode busbar at positions where the movable contact pieces on both sides of the guide groove of the case can come into contact with each other.

"Example" An upper storage chamber 2 and a lower storage chamber 3 are provided in an insulating case 1. The upper storage chamber 2 and the lower storage chamber 3 are communicated through a guide groove 4. A mounting groove 5 is formed below the lower storage chamber 3. A lever 7 whose lower end surface is formed as a cam surface 6 is placed in the upper housing chamber 2, and the cam surface 6 is brought into contact with the lower wall 8 thereof, and the end thereof is positioned in the vertical guide elongated hole 9 carved in the vertical wall. It is housed so as to be rotatable around the pivot shaft 10.

The upper end of a connecting plate 12 made of sheet metal and having a seat piece 11 protruding left and right in the center is pivotally connected to the support shaft 10, and a central part of a rectangular movable contact piece 13 made of sheet metal is externally fitted below it. A coil spring 15 is fitted and compressed between the movable contact piece 13 and a seat plate 14 provided at the lower end of the connecting plate 12 to bias the movable contact piece 13.

The upper part of the connecting plate 12, the movable contact piece 13, and the coil spring 15 thus formed are housed in the guide groove 4, the lower housing chamber 3, and the mounting groove 5, respectively.

A return coil spring 17 is fitted and compressed onto the connecting plate 12 between the downward engaging step portion 16 formed in the guide groove 4 and the seat piece 11 .

A locking groove 18 and a through hole 19 are provided at positions where the movable contact piece 13 can abut on both sides of the guide groove 4 of the case 1, respectively, and a pullout terminal 20 and a neutral electrode bus bar 21 are provided.
Set up. The lead-out terminal 20 is formed by forming a plate material into a closed square shape and screwing a screw 22 thereon, and the neutral electrode bus bar 21 is a plate-shaped body that is fitted into the through hole 19.

Further, a locking groove 23 is provided above the through hole 19 and on the case 1, a rectangular parallelepiped voltage terminal 24 is mounted therein, and a screw 25 is screwed into the locking groove 23.

"action" FIG. 2 shows the off state, and FIG. 3 shows the on state.

When the lever 7 is rotated in the direction of the arrow in the state shown in FIG. 2, the cam surface 6 of the lever 7 rotates while contacting the lower wall 8 of the upper accommodation chamber 2, and the lever 7 is lifted by the cam surface 6. The support shaft 10 moves upward in the guide elongated hole 9, the connecting plate 12 also moves upward and compresses the return spring 17, and the coil spring 15 causes the movable contact piece 13 to move between the lead-out terminal 20 and the neutral pole bus 21.
, the state shown in Figure 3 is reached, and the switch is turned on.

To turn off the cam surface 6, rotate the lever 7 in the direction shown by the arrow from the state shown in FIG.
comes into contact with the lower wall 8, and under the force of the return spring 17, the support shaft 10 and the connecting plate 12 move downward, and are separated from the movable contact piece 13, the lead-out terminal 20, and the neutral pole bus bar 21.

The principle of operation of this neutral pole switching device is as shown in FIG. That is, in the illustrated state, the movable contact piece 13 is pulled upward by the lever 7 and the connecting plate 12 and comes into contact with the pull-out terminal 20 and the neutral pole busbar 21, and in this state, the lever 7 is engaged with the lower wall 8. At the same time, it is supported by the coil spring 15. When lever 7 is rotated in the direction of the arrow,
Due to the engagement relationship between the lever 7 and the lower wall 8, the support shaft 10 is
The movable contact piece 13 moves to the lower position shown by the dotted chain line.
also moves downward and separates from the lead-out terminal 20 and the neutral electrode wire 21.

"Effect of the invention" As described above, the present invention provides an upper storage chamber and a lower storage chamber in the insulator case, communicates the upper storage chamber and the lower storage chamber with a guide groove, and connects the lower storage chamber with the lower storage chamber. A mounting groove is formed in the lever, and a lever with a cam surface formed on the lower end surface is placed in the upper housing chamber, with the cam surface abutting the lower wall thereof, and the end portion positioned within the vertical guide elongated hole carved in the vertical wall. The connecting plate is housed so as to be rotatable around a supporting shaft, and the upper end of the connecting plate having a catch piece protruding from the center is pivoted to the supporting shaft, and a movable contact piece is externally fitted below the connecting plate, and the connecting plate is slidable. A coil spring is fitted and contracted between the movable contact piece and a seat plate provided at the lower end of the connecting plate to bias the movable contact piece, and the upper part of the connecting plate, the movable contact piece, and the coil spring are connected to the guide groove. The movable contact pieces on both sides of the guide groove of the case are accommodated in the lower housing chamber and the mounting groove respectively, and a return coil spring is fitted and compressed on the connection plate between the engagement step formed in the guide groove and the seat piece. This is a neutral pole switching device for a distribution board that has a lead-out terminal and a neutral pole bus bar placed in positions where they can come into contact with each other.It turns on when the spring is energized and turns off when the spring is de-energized, matching the operation of a molded circuit breaker. There is no confusion in operation and there is no risk of erroneous operation. In addition, in order to connect the conventional one by turning it on when the spring is deenergized,
Even if the compressed length of the spring is short, sufficient pressing force must be applied, and the case may be damaged in order to increase the spring force.However, in this invention, the spring is turned off when the spring is deenergized, so the spring force is reduced. is not stronger than necessary, and there is no need to make the case thicker than necessary. Furthermore, in the present invention, the support shaft moves up and down in response to the rotation of the lever, and the on/off state is reliably maintained by the cam surface and the case. Furthermore, the present invention uses a hanging method to bring the movable contact pieces into contact, as opposed to the conventional method of pressing the movable contact pieces into contact, so the width of the case can be shortened and the neutral pole switching device can be made more compact.

[Brief explanation of the drawing]

The drawings show a specific embodiment of the present invention: Fig. 1 is an exploded perspective view, Fig. 2 is a front view showing the off state, Fig. 3 is a front view showing the on state, and Fig. 4 is the neutral state. It is a figure explaining the principle of operation of a pole switching device. DESCRIPTION OF SYMBOLS 1... Case, 2... Upper accommodation chamber, 3... Lower accommodation chamber, 4... Guide groove, 5... Mounting groove, 6... Cam surface, 7... Lever, 8... Lower wall, 9... ... Guide slot, 10 ... Support shaft, 11 ... Seat piece, 12 ... Connection piece, 13 ... Movable contact piece, 14 ... Seat plate, 15
... Coil spring, 18 ... Engagement stepped portion, 17 ... Return coil spring, 20 ... Output terminal, 21 ... Neutral pole bus bar.

Claims (1)

[Scope of utility model registration request] An upper storage chamber and a lower storage chamber are provided in the insulator case, the upper storage chamber and the lower storage chamber are communicated with each other through a guide groove, a mounting groove is formed below the lower storage chamber, and the lower end surface is formed into a cam surface. The lever is housed in the upper storage chamber so that the cam surface is in contact with the lower wall thereof and the lever is rotatable around a support shaft whose end is located in a vertical guide elongated hole carved in the vertical wall. The upper end of the connecting plate with the catch piece protruding from the center is pivotally connected to the support shaft, and a movable contact piece is externally fitted and slidably provided below the connecting plate, and the movable contact piece and the connecting plate are provided at the lower end of the connecting plate. A coil spring is externally fitted and contracted between the seat plate and the movable contact piece, and the upper part of the connecting plate, the movable contact piece part, and the coil spring part are accommodated in the guide groove, the lower accommodation chamber, and the mounting groove, respectively, and the guide groove A return coil spring is externally fitted and compressed on the connecting plate between the engagement step and the seat piece formed in A neutral pole switching device for a distribution board characterized by arranging.