JPH0622964Y2 - Electromagnetic device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an electromagnet device used for an earth leakage breaker.

[Prior Art] Conventionally, an electromagnet device of this type used for an earth leakage breaker is provided with a cylindrical exciting coil 1 and surrounding the exciting coil 1 as shown in FIGS. 5 and 6. The U-shaped yoke 2 having a plunger insertion hole 3 corresponding to the inner hole 1a of the excitation coil 1 on one leg 2a, and the excitation coil 1 through the plunger insertion hole 3 of the yoke 2. Is formed by a rod-shaped plunger 4 having one end inserted into the inner hole 1a and an actuator portion 5 formed at the other end, and a return spring 6 for urging the plunger 4 toward the actuator portion in the axial direction. As the plunger 4, as shown in FIG. 6 (a), a prismatic magnetic body in which a plurality of magnetic material plates are laminated, or a cylindrical magnetic body as shown in FIG. 6 (b) is used. It was

[Problems to be Solved by the Invention] However, in the above-described conventional example, when the exciting coil 1 is energized and the plunger 4 is pulled into the exciting coil 1, the leg piece 2a of the yoke 2 is pierced. There is a problem that a large frictional force is generated between the plunger 4 and the inner surface of the provided plunger insertion hole 3 and the plunger 4 is not driven smoothly. That is, when an exciting current flows through the exciting coil 1, an attractive force that pulls the plunger 4 into the exciting coil 1 so as to reduce the magnetic resistance of the magnetic circuit formed by the U-shaped yoke 2 and the plunger 4. As it occurs, the outer surface of the plunger 4 (the central piece 2 of the yoke
A suction force is also generated between the sliding contact surface (b) and the inner surface of the plunger insertion hole 3 of the yoke 2 (the sliding surface of the center piece 2b of the yoke 2). Here, in the conventional example, since the plunger has a columnar shape, the sliding contact area becomes large and a large frictional force is generated between the sliding contact surfaces, which hinders the smooth sliding of the plunger 4. Was there.

The present invention has been made in view of the above points, and an object of the present invention is to reduce the sliding contact area between the outer surface of the plunger and the inner surface of the plunger insertion hole of the yoke to reduce the sliding surface area. An object of the present invention is to provide an electromagnet device capable of smoothly sliding the plunger by reducing the frictional force of.

[Means for Solving the Problems] The electromagnet device of the present invention is a cylindrical exciting coil, and a plunger inserted through one leg corresponding to the inner hole of the exciting coil and arranged so as to surround the exciting coil. A U-shaped yoke having a hole formed therein, a rod-shaped plunger having one end inserted into the inner hole of the exciting coil through the plunger insertion hole of the yoke and an actuator portion formed at the other end, and the plunger In the electromagnet device formed by a return spring for urging the shaft toward the actuator portion side in the axial direction, the plunger is formed by bending the magnetic plate so that the cross section orthogonal to the axial direction has a U shape. At the same time, the plunger insertion hole is a square hole, and the plunger is inserted into the inner hole of the exciting coil through the plunger insertion hole so that the opening side of the U-shaped plunger is on one side of the center of the yoke.

[Operation] The present invention is configured as described above, and has a cylindrical exciting coil, a U-shaped yoke, and a plan end inserted into the inner hole of the exciting coil through the plunger insertion hole of the yoke. In an electromagnet device formed by a jar and a return spring,
The plunger is formed by bending a magnetic plate so that the cross section orthogonal to the axial direction is U-shaped, and the U-shaped plunger is inserted in the plunger insertion hole consisting of a square hole so that the opening side is the center of one side of the yoke. It is inserted so that only the end faces of both legs of the plunger are in sliding contact with the inner surface of the plunger insertion hole, so there is no sliding between the outer surface of the plunger and the inner surface of the plunger insertion hole of the yoke. The contact area is reduced, the frictional force between the sliding contact surfaces can be reduced, and the plunger can be slid smoothly.

[Embodiment] FIGS. 1 to 4 show an embodiment of the present invention, in which a cylindrical exciting coil 1 and one leg 2a arranged so as to surround the exciting coil 1 have an exciting coil. U-shaped yoke 2 having a plunger insertion hole 3 corresponding to the inner hole 1a
A rod-shaped plunger 4 having one end inserted into the inner hole 1a of the exciting coil 1 through the plunger insertion hole 3 of the yoke 2 and an actuator portion 5 formed at the other end; In an electromagnet device similar to the conventional example, which is formed by a return spring 6 that urges the actuator portion 5 side,
The plunger 4 is formed by bending the magnetic plate so that the cross section orthogonal to the axial direction has a U-shape, and the plunger insertion hole 3 is a square hole.
The plunger 4 is inserted into the inner hole 1a of the exciting coil 1 through the plunger insertion hole 3 so that the opening side of the yoke 2 is on the side of the central piece 2b of the yoke 2. In this embodiment, a leakage display mechanism is incorporated, a display button 10 is provided at the upper end, and a square hole 11 through which the plunger 4 is inserted.
The display body 12 having the above, the coil spring 13 that biases the display body 12 upward, and the notch formed in the plunger 4 form a leakage display mechanism, and when the plunger 4 is driven to the left, The lower edge of the square hole 11 of the display body 12 is fitted into the notch 14, the display body 12 is driven upward by the coil spring 13, and the display button 10 is projected to cause the occurrence of electric leakage (of the electromagnet device for cutting off electric leakage). (Operation) is notified.

The operation of the embodiment will be described below. Now, when an exciting current flows through the exciting coil 1, the yoke 2 and the plunger 4
A magnetic circuit is formed by and, an attractive force that pulls the plunger 4 into the inner hole 1a of the exciting coil 1 is generated, and the plunger 4 is driven leftward against the spring force of the return spring 6. When the electromagnet device of the present invention is incorporated in an earth leakage breaker, and an exciting current is passed through the exciting coil 1 by an earth leakage detection signal, the leakage breaker is formed by the actuator portion 5 formed at the other end of the plunger 4. The trip mechanism latch is pulled out, and the circuit break contact is turned off. By the way, the plunger 4 is the exciting coil 1.
When it is drawn into the inner hole 1a and driven leftward, a suction force is generated between the outer surface of the plunger 4 and the inner surface of the plunger insertion hole 3, and a frictional force is generated between the sliding contact surfaces. In the present invention, since only the end surfaces of the two leg pieces of the plunger 4 are in sliding contact with the inner surface of the plunger insertion hole 3, there is a gap between the outer surface of the plunger 4 and the inner surface of the plunger insertion hole 3. The sliding contact area is significantly smaller than the conventional example, and the frictional force between the sliding contact surfaces can be reduced,
The plunger 4 can be slid smoothly. That is, as shown in FIG. 2, only the portion A of the plunger 4 comes into sliding contact with the inner surface of the plunger insertion hole 3 of the yoke 2, so that the frictional force can be reduced. The outer surfaces of both leg pieces of the plunger 4 are in contact with the inner surface of the plunger insertion hole 3 as in the conventional example, so that the axial driving force of the plunger 4 can be secured. Also, the plunger 4
Since the magnetic material plate punched into a predetermined shape can be easily formed by sheet metal processing for bending into a U shape, the cost can be reduced.

[Advantage of the Invention] The present invention is configured as described above, and one end is inserted into the inner hole of the exciting coil through the cylindrical exciting coil, the U-shaped yoke, and the plunger insertion hole of the yoke. In the electromagnet device formed by the plunger and the return spring,
The plunger is formed by bending a magnetic plate so that the cross section orthogonal to the axial direction is U-shaped, and the U-shaped plunger is inserted in the plunger insertion hole consisting of a square hole so that the opening side is the center of one side of the yoke. It is inserted so that only the end faces of both legs of the plunger are in sliding contact with the inner surface of the plunger insertion hole, so there is no sliding between the outer surface of the plunger and the inner surface of the plunger insertion hole of the yoke. The contact area is reduced, the frictional force between the sliding contact surfaces can be reduced, and the plunger can be slid smoothly.

[Brief description of drawings]

1 and 2 are sectional views of an embodiment of the present invention, and FIG.
FIG. 4 is a side view of the same as above, FIG. 4 is a top view of the same as above, FIG. 5 is a sectional view of a conventional example, and FIGS. Reference numeral 1 is an exciting coil, 2 is a yoke, 2a is a leg piece, 2b is a center piece, 3 is a plunger insertion hole, 4 is a plunger, 5 is an actuator portion, and 6 is a return spring.

Claims (1)

[Scope of utility model registration request] 1. A U-shaped yoke having a cylindrical exciting coil and a plunger insertion hole formed in one leg so as to surround the exciting coil and corresponding to an inner hole of the exciting coil. When,
A rod-shaped plunger having one end inserted into the inner hole of the exciting coil through the plunger insertion hole of the yoke and an actuator portion formed at the other end, and a return spring for urging the plunger toward the actuator portion in the axial direction. In the electromagnet device formed by and, the magnetic body plate is bent so that the cross section orthogonal to the axial direction is U-shaped to form the plunger, and the plunger insertion hole is a square hole, An electromagnet device characterized in that the plunger is inserted into the inner hole of the exciting coil through the plunger insertion hole so that the opening side of the mold type plunger is located on one side of the center of the yoke.