JPS5824892B2 - electromagnetic device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention is an electromagnetic device equipped with a movable iron core or a plunger that is attracted when an excitation coil is excited, and in particular an electromagnetic device that drives a driven object by utilizing the protrusion of the plunger due to deenergization of the excitation coil. This invention relates to an improvement in an electromagnetic device.

Conventionally, this type of electromagnetic device is used, for example, in an undervoltage trip device that is built into a circuit breaker and automatically trips the circuit breaker when the circuit voltage drops or a power outage occurs.

An undervoltage trip device has a structure in which an electromagnetic solenoid converts electrical energy into kinetic energy and drives the trip mechanism to perform a tripping operation.The electromagnetic solenoid stores spring energy and reduces the voltage. When the attraction force of the electromagnetic solenoid becomes less than the force of the spring, the solenoid is released by the force of the spring and uses that energy to perform the pulling process.

Generally, the attraction force of an electromagnetic solenoid becomes larger as the air gap becomes smaller.

Therefore, when the plunger is completely attracted to the fixed core, the air gap is O and the attracting force is maximum, and in this state, the attracting force of the electromagnetic solenoid due to the voltage drop is overcome, and the plunger is released from the fixed core. The spring force is also maximum.

In addition, in order to attract the plunger to the fixed core again, a strong electromagnetic force is required to counteract the force of the spring, which increases the size of the electromagnetic device and increases power loss. There is.

The present invention provides a small electromagnetic device that can be built into or attached to a circuit breaker and similar equipment by applying an acting force that counteracts the attraction force of an electromagnetic solenoid when voltage drops, thereby reducing the attraction force. It is something.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below with reference to the drawings based on an example in which the present invention is implemented in an undervoltage cutoff device for a circuit breaker.

That is, in FIGS. 1 and 2, 12 is an excitation coil of an electromagnetic solenoid, 11 is a plunger that is inserted into the excitation coil 12 and is attracted by the excitation of the excitation coil, and 9 is a magnet that is attracted by the plunger and pin 10. The plunger rod A is integrally formed, and the other end of the rod A is slidably supported by the frame 1.

Reference numeral 19 denotes an adjustment screw screwed into the middle portion of the rod A as a convex portion for suppressing the lever, which holds the roller 7, which will be described later, from being released when the electromagnetic solenoid is in the suction state.

6 is an L that rotates around a pin 5 fixed to the frame 1.
a rotary lever in the form of a rotary lever, one arm of which is operatively connected so as to fit loosely into the rod A9 and constantly abut against the adjusting screw 19;
The other arm has a roller pin 8 and a roller 7 that rotates around the roller pin 8.

Reference numeral 2 denotes an operating lever that rotates around a pin 18 fixed to the frame 1, and has a tapered latch 4 connected to the pin 3 at one end, and a rod connected to the pin 3 at the other end. It has B15.

The latch 4 has a tapered locking portion formed in a substantially dogleg shape so as to apply a rotational force to the rotary lever 6, and is loosely fitted into the pin 5 of the rotary lever 6 through an elongated hole.

14 is a circuit breaker tripper connected by rod B15; 13 is a nut screwed onto rod B15;
Reference numeral 17 denotes a torsion spring whose twist portion is fitted into the pin 18 and whose ends are locked to the frame 1 and the actuating lever 2, so as to always bias the actuating lever 2 in the counterclockwise direction.

The energy stored in the torsion spring 17 due to the protrusion of the plunger 11 rotates the tripper 14 counterclockwise to trip the circuit breaker.

Numeral 16 is inserted between frame 1 and a nut 20 screwed onto rod A9 so as to push the plunger 11 out when the excitation coil is deenergized.

In FIG. 1, the electromagnetic solenoid is energized and the circuit breaker is closed.

First, a reset mechanism (not shown) causes the torsion spring 1 to
The energy stored in 7 is held in place by a latch consisting of latch 4 and roller I.

Since the latch 4 has a dogleg-shaped taper as a locking part, the energy F generated by the torsion spring 17 is transferred to the force R acting downward along the tapered surface and the contact surface as shown in FIG. This is the vertical component force S that acts.

Due to these two component forces, the rotary lever 6 always tries to rotate clockwise.

The above acting force and the spring force of the push spring 16 accumulated due to the suction of the plunger 11 cause the plunger 11 to move due to the voltage drop.
When the suction force exceeds , the plunger is released by the force of the push spring 16 and protrudes, and the roller 7 is automatically disengaged due to the above acting force, and the energy stored in the torsion spring 17 rotates the actuating lever 2 counterclockwise. The tripper 14 is rotated counterclockwise by the rod 15 to trip the circuit breaker.

That is, the undervoltage series disconnection device automatically trips the circuit breaker when the attraction force of the plunger due to the voltage drop becomes less than the spring force of the push spring 16 plus the release force of the latch.

This device also requires a reset operation to re-energize the circuit breaker.

Next, the reset operation will be explained.

First, a reset mechanism (not shown) resets the tripper 1.
4 clockwise, and rotate the operating lever 2 until it is in the state shown in FIG.

At this time, if a voltage is applied to the excitation coil 12, the plunger 11 is attracted and compresses the pusher spring 16.

The suction action of the plunger 11 causes the rotary lever 6 to rotate counterclockwise to engage the roller 7 with the latch 4, completing the reset action.

Further, when no voltage is applied to the excitation coil 12 or when the voltage is low, the plunger 11 cannot compress the push spring 16, so the plunger 11 is not attracted, so the roller 7 and the latch 4 cannot engage and the twist spring Since the tripper 14 is rotated by the above-described operation using the energy of the tripper 17, the circuit breaker cannot be turned on, so a drop in voltage can be easily determined, and there is no risk of erroneous operation.

As explained above, the attraction force caused by the drop in voltage of the electromagnetic solenoid is reduced by the releasing force of the latch, and the rotating lever 6 rotates smoothly due to the dogleg-shaped locking part of the latch 4, so the plunger 11 The spring force of the push spring 16 that releases the iron from the fixed iron core becomes smaller.

However, in order to cause the protruding plunger 11 to be attracted to the fixed iron core again, the spring force of the push spring 16 may be small.
A small electromagnetic solenoid can be used, and an electromagnetic device can be miniaturized and one with low power loss can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are block diagrams showing one embodiment of the present invention, with FIG. 1 showing the suction state and FIG. 2 showing the release state. FIG. 3 is a diagram showing details of the latch portion according to the invention. In the figure, 2 is an operating lever, 4 is a latch, 6 is a rotating lever, 7 is a roller, 9 is a rod, 11 is a plunger,
12 is an excitation coil, 17 is a torsion spring, and 19 is an adjustment screw.

Claims (1)

[Claims] 1. An excitation coil consisting of an electromagnetic solenoid, a plunger that is inserted into the excitation coil and is attracted and driven when the excitation coil is excited, and one end supported by the plunger and the other end slidably supported by a frame. a plunger rod having a protrusion for pressing the lever in its intermediate portion; a push spring that is attached between the plunger rod and the frame and urges the plunger rod in a direction opposite to the suction direction; an L-shaped rotary lever that is rotatably supported by a pin supported on the frame and comes into contact with the convex portion of the plunger rod; a roller that is rotatably attached to the tip of the rotary lever; A latch is loosely fitted to the pin of the lever through an elongated hole, and the other end of the latch is provided with a substantially dog-shaped locking part that engages with the lever and applies rotational force to the rotating lever. The latch member is provided with an actuation lever that is movably engaged and urges the latch in a predetermined direction, and the latch member is configured such that the urging force of the push spring and the actuation lever is released from the state in which the dogleg-shaped locking portion and the roller are in contact with each other. An electromagnetic device configured to release the locked state from the roller when the attraction force of the plunger by the excitation coil becomes greater.