JPS61284024A - Electric switch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electrical switch used, for example, as a main switch of a distribution board.

[Conventional technology]

A conventional electrical switch of this type is shown in FIG.

FIG. 7 is a side sectional view showing the ON state. In the figure,
(1) is a casing made of insulating material, and C) is an operating handle rotatably supported around a support shaft (1a) that is a part of the casing (1).・The opening of the casing (1) It projects outward from the portion (1b). (3) The coil part (3a) is connected to the support shaft (1a
), the handle spring (4) is a movable element rotatably supported by a shaft (5) supported by the housing (1),
One end is connected to the operating handle (2) by a link (6).

('7) is the opening/closing spring hung on the pin (4a) of the mover (4), (8) is the movable contact fixed to the other end of the mover (4), and (9) is attached to the housing (1). A fixed stator, (10) is a fixed contact fixed to the stator (9) so as to face the movable contact (8), (1) is a terminal electrically connected to the stator (9), An external conductor (not shown) is connected by a wire presser (Il&) and a screw (llb). (12)
is a flexible copper stranded wire whose one end is electrically connected to the mover (4), and (13) is a terminal to which the other end of the flexible copper stranded wire (12) is electrically connected. 13a) and screw (13b)
and connects an external conductor (not shown).

Next, the operation will be explained. Operation handle C2) wo arrow (14
), it is pulled by the link (6) and the movable element (4) rotates clockwise, opening and opening the movable contact (8). In other words, it becomes an OFF operation.Then, in the opposite direction to the arrow (14) When the operating handle (2) is returned to the position shown in the figure, the movable element (4) is pushed by the link (6) and rotates counterclockwise, and the movable contact (8) closes. Become.

[Problem that the invention seeks to solve]

In conventional electrical switches such as those described above, if a large current flows due to an accident or other reason when the contact is opened, an electromagnetic repulsion force of the concentrated current is generated at the contact, causing the movable contact (8) to rise, causing an arc and causing contact wear and tear. There is a problem that welding may occur in some cases.

This invention was developed to solve this problem, and provides an electric switch that can prevent the movable contacts from floating when a current exceeding a predetermined value flows, thereby preventing wear and welding of the contacts. The purpose is to

[Means for solving problems]

The electric switch according to the present invention is equipped with an electromagnetic device having a coil connected in series to both contacts and a plunger that is activated when a current of a predetermined value or more flows through the coil.0 [Function] This invention In this case, when the coil of the electromagnetic device is energized by a current exceeding a predetermined value, the plunger energizes the movable element in the closed state in the closing direction, thereby preventing one movable contact from floating.

[Embodiments of the invention]

FIGS. 1 to 6 are diagrams showing an embodiment of the present invention,
Figures 1 and 2 show its OFF state, and Figure 3 shows its ON state.
FIGS. 4 to 6 are diagrams each showing an ON state (a state in which a fault current flows) in which the mover is biased in the closing direction by an electromagnetic device. In the figure, (1) to (13) are exactly the same as the conventional device described above. (15) has one end electrically connected to the stator (9) and the other end to the terminal (15).
The coil (16) is electrically connected to the housing (1).
) is attached to the yoke to form a magnetic path, (17) is a fixed iron core attached to the yoke (16), and (18) is a yoke that resists the spring force of the push spring (19) when the coil (15) is energized. The plunger is sucked in the direction of the arrow (20) in Figures 1 and 2, and (21) is the tip (18) of the plunger (18).
The push spring (19), which is an insulating bush that engages the plunger (M) with the recess (4b) of the mover (4), prevents the plunger (18) from being attracted at the rated current, and Prevents welding due to excessive contact pressure of the movable contact (8).

Next, the operation will be explained. In the OFF state shown in Fig. 1, when the operation handle (2) is operated in the direction of the arrow (22), the mover (4) is pushed by the link (6) and rotates counterclockwise, as shown in Fig. 3. The movable contact (8) closes. That is, it is an ON operation. If the current is less than a predetermined value in the ON state of FIG. 3, the plunger (18) is energized by the coil (15) but cannot overcome the pressure spring (19), so the plunger (18) It doesn't move. Therefore, as shown in FIG. 3, only the movable element (4) rotates. When the operating handle (2) is operated in the direction of the arrow (23) in the ON state shown in Fig. 3, the mover (4) is pulled by the link (6) and rotates clockwise, as shown in Fig. 1. This is a 0, ie, OFF operation in which the movable contact (8) opens and closes.

Next, when a current of more than a predetermined value flows in the ON state shown in FIG.
) is attracted and energized and presses the movable element (4) in the closing direction as shown in Figs. This pressing force prevents the movable contact (8) from lifting up.

Note that, as shown in FIG. 5, since a gap (24) is provided between the plunger (18) and the fixed iron core (17), the pressing force of the movable element (4) changes depending on the magnitude of the current. In other words, the larger the current, the larger the pressing force, so
A pressing force matching the magnitude of the electromagnetic repulsive force is obtained, and the movable contact (8) becomes the fixed contact (10) due to the pressing force more than necessary.
Also, due to insufficient pressing force, the movable contact (8
) can be prevented from rising.

〔Effect of the invention〕

As explained above, the present invention has the effect of preventing the movable contact from floating when a current of more than a predetermined value flows, thereby preventing wear and welding of the contact.

[Brief explanation of drawings]

1 to 6 show one embodiment of the present invention, FIG. 1 is a side sectional view showing the OFF state, FIG. 2 is a side sectional view of the main part of FIG. 1, and FIG. 4 is a side sectional view showing the ON state in which the mover is biased in the closing direction by an electromagnetic device. FIG. 5 is a side sectional view of the main part of FIG. FIG. 6 is a view of only the mover in FIG. 5 seen from the left, and FIG. 7 is a side sectional view showing a conventional electric switch. In the figure, (2) is the operation handle, (4) is the movable element,
(8) is a movable contact, (10) is a fixed contact, (15) is a coil, and (18) is a plunger. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Patent Attorney Masuo Oiwa c-a-1i
61 lQ cheap +1 Figure 2 Figure 6 Figure 5

Claims (1)

[Claims] (1) In an electric switch that has a fixed contact, a movable element having a movable contact, and an operation handle that opens and closes the movable element, a current of a predetermined value or more flows through a coil connected in series to both the contacts and this coil. An electric switch comprising: an electromagnetic device having a plunger that is activated when the coil is activated, and the plunger urges the movable element in a closing direction when the coil is activated.