JP3251991B2 - Manufacturing method of relay iron core - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a relay iron core, particularly a U-shaped iron core.

[0002]

2. Description of the Related Art As shown in FIG. 5, an iron core 1 having a U-shape and having a coil 3 wound around a central portion has a thickness b at a central portion and a thickness a at magnetic pole portions 11 at both ends. Are configured to satisfy a ≦ b when compared with each other. In this case,
When the distance between the contacts is widened to improve the withstand voltage between the contacts and the stroke of the armature is increased in accordance with this, as shown by the broken line in FIG. Will not be able to match.
For this reason, as shown in FIG. 7, in order to obtain the above-mentioned alignment margin, it has been considered that the central portion of the iron core 1 is forged so that the thickness b becomes smaller than the magnetic pole portions a at both ends.

[0003]

However, in this case, as shown in FIG. 8, the crystal grains during the heat treatment (pulverization) of the central portion whose thickness has been reduced by forging do not progress, and the processing strain is reduced. Are left, resulting in poor magnetic characteristics (see FIG. 3a. Incidentally, the crystal grains in the conventional example shown in FIG. 5 are shown in FIG. 6, and the BH characteristics in this conventional example are shown in FIG. b).

[0004] The present invention has been made in view of the above problems, and has a matching margin between the spring load and it is an object of magnetic properties good relay iron core
An object of the present invention is to provide a method of manufacturing a relay core that can be easily obtained .

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention relates to a method of manufacturing a relay iron core having a U-shape, in which a coil is wound around an outer periphery of a central portion and both ends are magnetic pole portions acting on an armature. The required rolling rate at both ends of the material
The wall thickness is made thicker than the central part by non-forging method,
It is characterized in that a stepped material is bent into a U-shape .

[0006]

[Action] Relay iron core thus obtained in the present invention are those suction force due to the large pole area thick pole portions at both ends is increased, also the central unit inhibits the expansion of crystal grains during the heat treatment Since there are no factors, the magnetic characteristics do not deteriorate.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the illustrated embodiment. As shown in FIG. 1, a coil 2 is wound around a central portion via a coil frame 3 and both ends are provided with magnetic pole portions 11 as shown in FIG.
The U-shaped iron core 1 has magnetic pole portions 11 at both ends thereof.
Is larger than the thickness b of the central portion, but this difference in thickness is not obtained by forging the central portion or the like, as shown in FIG. 1 (b). It is formed by bending a stepped material 1 ′ having both ends thick and a center portion thin by cutting or the like into a U-shape, and for this purpose, the coil 2 is wound. The central portion and the magnetic pole portions 11 at both ends have substantially the same rolling reduction (10 to 14%).

For this reason, in the central portion of the iron core 1, as shown in FIG.
Therefore , as shown by c in FIG. 3, it is possible to obtain almost the same magnetic characteristics as the conventional example shown in FIG.
Moreover, since the thickness of the magnetic pole portions 11 at both ends is large and the magnetic pole area is large, even if the stroke of the armature becomes large, as shown in FIG. This has a sufficient matching margin with the spring load c.

[0009]

As described above, the production method of the present invention
Relay cores have thick magnetic poles at both ends and a large magnetic pole area, which increases the attractive force.The central part has no factor that hinders the expansion of crystal grains during the heat treatment. Good characteristics can be obtained without deteriorating the magnetic characteristics.

[Brief description of the drawings]

FIGS. 1A and 1B show an embodiment, in which FIG. 1A is a sectional view and FIG. 1B is a front view of an iron core material.

FIG. 2 is an enlarged view showing crystal grains of an iron core according to the first embodiment.

FIG. 3 is an explanatory diagram showing magnetic characteristics of the above.

FIG. 4 is an explanatory diagram showing operation characteristics of the above.

FIG. 5 is a sectional view of a conventional example.

FIG. 6 is an enlarged view showing the same crystal grains.

FIG. 7 is a front view of another conventional example.

FIG. 8 is an enlarged view showing the same crystal grains.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Iron core 2 Coil 11 Magnetic pole part

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-295123 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01H 49/00-51/36

Claims (2)

(57) [Claims] 1. A two ends with a U-shaped coil in the central portion outer peripheral wound is a manufacturing method of a relay iron core which has a magnetic pole portion which acts on the armature, the required pressure
The thickness of both ends of the material with the elongation is made thicker than the central part
And make the stepped material bent into a U-shape.
Method for producing a relay iron core, characterized in that that. 2. Use of a material having a rolling reduction of 10 to 14%.
The method for manufacturing a relay core according to claim 1, wherein: