JPH0727820B2 - Electromagnetic device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a plunger-type electromagnet device.

BACKGROUND ART Conventionally, a plunger type electromagnet device of this type is housed in a yoke 1 having a U-shape as shown in FIG. 4, and is housed in the yoke 1 so that both end surfaces respectively face both yoke leg pieces 1a. A cylindrical exciting coil 2 and a plunger 5 whose tip is slidably inserted into an inner hole 3 of the exciting coil 2 through an insertion hole 4 formed in the yoke leg 1a; 1 and a coil spring 6 that urges the plunger 5 in the return direction.
A stopper piece 10 made of a non-magnetic material is provided with a hooking claw 10a for hooking engagement with the periphery of the insertion hole 9 of 1a, and a caulking fixing portion 10b for the plunger 5 at the other end. Was being planned. However, in such a conventional example, since a special member (retaining piece 10) is added as a retaining mechanism for the plunger 5, the number of parts is increased and the assembly becomes troublesome. There was a problem that the cost was high.

[Object of the Invention] The present invention has been made in view of the above points, and an object of the present invention is to reduce the number of parts, simplify the assembly, and reduce the cost. To provide.

DISCLOSURE OF THE INVENTION (Embodiment) FIG. 1 to FIG. 3 show an embodiment of the present invention, which is a U-shaped yoke 1 and a yoke so that both end surfaces respectively face both yoke leg pieces 1a. 1. A cylindrical exciting coil 2 housed in 1 and a plunger 5 having a tip 5a slidably inserted into an inner hole 3 of the exciting coil 2 through an insertion hole 4 formed in a yoke leg 1a. In the same electromagnet device as in the conventional example, which includes a coil spring 6 which is interposed between the spring receiving projection 5b of the plunger 5 and the peripheral portion of the insertion hole 4 of the yoke leg piece 1a and biases the plunger 5 in the returning direction, A notch 7 is provided in the center of the plunger 5, and the shapes of the inner hole 3 and the insertion hole 4 of the exciting coil 2 are made substantially the same as the cross-sectional shape of the tip 5a of the plunger 5, and one portion of the peripheral surface of the yoke 1 is Center piece 1b
The insertion hole 4 is provided in the inner hole 3 of the exciting coil 2 arranged so as to abut on the opening 1 so as to be displaced by the depth of the notch 7 in the opening direction of the yoke 1. Here, in the embodiment, the step portion 8 on the tip side of the notch 7 is an inclined surface. Further, a magnetic plate having a rectangular cross section is used as the plunger 5, and an inner hole (square hole) having substantially the same cross-sectional shape as the tip portion 5b is used.
Although the rectangular tube-shaped exciting coil 2 in which the coil winding 2b is wound around the coil frame 2a having 3 is used, a magnetic rod having a square or circular cross section may be used. In this case, it goes without saying that the inner hole 3 and the insertion hole 4 are square or circular. The protrusion 5c protruding from the tip of the plunger 5 is for reducing the influence of the residual magnetism after the attraction.

The assembly procedure and operation of the embodiment will be described below. When assembling the electromagnet device according to the present invention, first, as shown in FIG. 3, the inner hole 3 of the exciting coil 2 and the insertion hole 4 of the yoke leg 1a are aligned with each other, and the tip portion of the plunger 5 is aligned. 5a is inserted into the inner hole 3 of the exciting coil 2 so that the return spring 6 is compressed. Plunger 5 like this
With the tip portion 5a of the coil inserted into the exciting coil 2, the exciting coil 2 is moved to a predetermined position as shown in FIG.
The inner hole 3 and the insertion hole 4 are eccentric to each other until the peripheral surface of the contacting portion of the yoke 1 comes into contact with the center piece 1b of the yoke 1, and the notch 7 at the center of the plunger 5 is engaged with the peripheral edge of the insertion hole 4 to assemble. Is completed. In this state, the stepped portion 8 of the notch 7 of the plunger 5 is engaged with the peripheral edge of the insertion hole 4 to realize the function of preventing the plunger 5 from coming off, so that the plunger 5 can be prevented from coming off without adding special parts. Since it is possible to reduce the number of parts, the assembly can be simplified and the cost can be reduced. Further, in the embodiment, since the stepped portion 8 of the notch 7 is an inclined surface, the minus operation in the suction operation is reduced. The suction force in the direction can be prevented, and stable operation can be performed.

[Advantages of the Invention] As described above, the present invention includes a U-shaped yoke, a cylindrical exciting coil housed in the yoke so that both end surfaces thereof face the yoke leg pieces, and the yoke leg piece. An electromagnet device including a plunger having a distal end slidably inserted into the inner hole of the exciting coil through an insertion hole formed therein, and a coil spring interposed between the plunger and the yoke and biasing the plunger in the return direction. In, the notch is provided in the center of the plunger, and the shapes of the inner hole and the insertion hole of the exciting coil are made substantially the same as the cross-sectional shape of the tip of the plunger.
The insertion hole is provided in the inner hole of the exciting coil arranged so that one part of the peripheral surface is in contact with the central piece of the yoke, and is shifted in the opening direction of the yoke by the depth of the notch. The notch engages with the peripheral edge of the insertion hole to prevent the plunger from coming off, and unlike the conventional example, a special part for preventing the plunger from coming off is not required.
This has the effects of reducing the number of parts, simplifying the assembly, and reducing the cost.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a perspective view of an essential part of the same, FIG. 3 is an exploded perspective view of the same, and FIG. 4 is a sectional view of a conventional example. 1 is a yoke, 2 is an exciting coil, 3 is an inner hole, 4 is an insertion hole,
5 is a plunger, 6 is a coil spring, and 7 is a notch.

Claims (1)

[Claims] 1. A U-shaped yoke, a cylindrical exciting coil housed in the yoke such that both end faces of the yoke leg piece face each other, and an insertion hole formed in the yoke leg piece. In the electromagnet device, the tip of which is slidably inserted into the inner hole of the exciting coil, and the coil spring which is interposed between the plunger and the yoke and biases the plunger in the return direction, has a notch at the center of the plunger. Of the exciting coil, the inner hole and the inserting hole of the exciting coil are made substantially the same in shape as the cross-sectional shape of the tip of the plunger, and the exciting coil is arranged so that one part of the peripheral surface abuts the central piece of the yoke. An electromagnet device, wherein an insertion hole is provided so as to be offset from the inner hole in the opening direction of the yoke by the depth of the notch.