JP3367337B2 - Electromagnet of magnetic contactor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnet for an electromagnetic contactor. 2. Description of the Related Art FIG. 3 shows a configuration example of a bridge type electromagnetic contactor which has been widely used as an electromagnetic contactor using an electromagnet according to the present invention. The electromagnetic contactor comprises an upper opening / closing contact portion and a lower electromagnet as described below. The pair of fixed contacts 25 is attached to the upper case 32 such that the terminal screw 25b screwed to the other end is exposed from the upper case 23 with the fixed contact 25a at one end inside. The movable contact support 22 is fixed to the movable core 21 accommodated in the upper case 32 and the lower case 31 by a pin (not shown) between the fixed contacts 25 so as to be movable up and down. The movable contact support 22 is provided with a movable contact 23 provided with a movable contact 23a capable of bridging between two fixed contacts 25a via a contact spring 24. An open / close contact portion formed by the fixed contact 25 and the movable contact 23 is covered by an arc extinguishing cover 33. The electromagnets housed in the lower case 31 and the upper case 32 are a bottom plate 15 made of a ferromagnetic material, a coil 14 wound around a spool 13 and fixed to the bottom plate 15, and a leg fitted into the spool 13. It comprises a fixed iron core composed of a part core 11, a pole piece 12 fixed to the movable iron core 21 side of the leg iron core 11, and a movable iron core 21 supported by a return spring 16. This movable iron core 21 is a pole piece 1
2, the movable contact support 22 is moved up and down. The assembling of the leg iron core 11 and the pole piece 12 is performed by aligning the pole piece 12a with the leg iron core 11a as shown in FIG. 4 and fixing with a screw 12b, or as shown in FIG. And the pole piece 12c are welded together and fixed at the welded portion 99 to be assembled. The space of the electromagnet with respect to the electromagnetic contactor is limited to some extent, and there is no space around the square pole piece 12, and the return spring 16 is arranged between the pole pieces 12. In this configuration, when the coil 14 is energized, the movable iron core 21 is attracted to the pole piece 12, whereby the movable contact support 22 descends and the movable contact 23a contacts the fixed contact 25a to close the main circuit. To achieve. Further, when the energization of the coil 14 is stopped and the movable iron core 21 is released from the pole piece 12 by the return spring 16, the movable contact support 22 rises and the movable contact 23a separates from the fixed contact 25a to open the main circuit. . In the above example, since the pole piece is fixed to the leg core by screws or welding, the contact reliability between the pole piece and the leg core depends on the looseness of the screw and welding. It depends on the occurrence of cracks in the parts, etc., and requires many man-hours for processing and assembling, and requires expensive manufacturing equipment for this processing. An object of the present invention is to provide an electromagnet having high contact reliability between a pole piece and a leg core and requiring a small number of processing steps. [0007] In order to achieve the above-mentioned object, the invention according to the first aspect is configured by connecting the other ends of two leg cores each having one end to which a pole piece is connected by a bottom plate. A movable core that is coupled to a fixed core, a coil wound around the leg core, and a movable contact support that holds a movable contact that comes into contact with and separates from the fixed contact, and is attracted by an electromagnetic force generated in a pole piece by a current flowing through the coil. In an electromagnetic contactor provided with an electromagnet consisting of an iron core, the outer peripheries of the pole pieces are
The opposite ends of the two pole pieces facing each other are
It formed in a linear shape, and wherein the two outer peripheral that does not face each other <br/> of the pole piece is formed in an arc shape. FIG. 2 shows an embodiment of the present invention.
(a) is a perspective view of a material, (b) is a processed state in which an upper mold is omitted, and (c) is a perspective view of a part. Round iron bar 7 of the material shown in (a)
1 is put into a mold 91 of (b), a force is applied from the P direction, and the lower part is plastically deformed by so-called cold forging to form the plastic core 1 of (c). Here, in order to increase the suction force of the pole piece portion, a slightly higher step 1a may be provided on the plane. One end of the pole piece portion of the plastic core 1 is linear in order to prevent magnetic leakage between the two pole piece portions, and the other end is asymmetrically formed into an arc or an elliptic arc because an effective magnetic flux for attracting the movable iron core is used. In order to increase. FIGS. 1A and 1B show the configuration of an electromagnetic contactor using the plastic core 1. FIG. 1A is a sectional view of a main part, and FIG. The same parts as those in FIG. 3 are denoted by the same reference numerals and description thereof will be omitted. A component other than the plastic core 1 and different from FIG. 3 is a return spring 3 instead of the return spring 16. With this shape, the efficiency of the closed magnetic path composed of the plastic core 1, the movable core 21, and the bottom plate 15 when the current flows through the coil 14 and the movable core 21 is attracted is always constant. If the plastic core 1 having the step 1a is used, the efficiency is further improved. Since the outer periphery of the pole piece portion is formed in an arc shape, an empty space is formed at a corner of the spool 13, and the two return springs 3 are used instead of the conventional return spring 16 by utilizing the space at the corner. Can be provided. According to the first aspect of the present invention, the outer peripheries of the pole pieces of the plastic core are paired with each other.
Opposing ends of two opposing pole pieces are linearly shaped
Since the outer circumferences of the two pole pieces that are not opposed to each other are formed in an arc shape , the suction force to the movable iron core is increased, the outer circumference space can be used as a return spring, and the size of the electromagnetic contactor can be reduced. [0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a structural view of an electromagnetic contactor according to an embodiment of the present invention, in which (a) is a cross-sectional view of a main part, and (b) is a cross-sectional view taken along arrow Q of (a). FIG. 2 is a view showing a manufacturing process of a plastic core according to the present invention;
(a) is a perspective view of the material, (b) is a perspective view during cold forging, in which the upper die is omitted, and (c) is a perspective view of the finished product. [Figure 3] Cross-sectional view of main parts of a conventional electromagnetic contactor [ FIG. 4 is an assembled perspective view of a leg core and a pole piece of a conventional electromagnetic contactor. FIG. 5 is another assembled perspective view of a leg core and a pole piece of a conventional electromagnetic contactor. Return spring 11 Leg core 12 Pole piece 14 Coil 15 Bottom plate 16 Return spring 21 Movable core 22 Movable contact support 24 Contact spring 33 Arc extinguishing cover

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-323808 (JP, A) JP-A-4-196202 (JP, A) JP-A-53-29562 (JP, A) 32345 (JP, U) Shokai 63-72829 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01H 50/36 H01H 51/06

Claims (1)

(57) [Claim 1] A fixed iron core formed by connecting the other ends of two leg iron cores having one end connected to a pole piece with a bottom plate, and a coil wound around the leg iron core. An electromagnetic contactor having an electromagnet composed of a movable iron core coupled to a movable contact support that holds a movable contact that comes into contact with and separated from the fixed contact, and is attracted by an electromagnetic force generated in a pole piece by a current flowing through the coil. The outer periphery of the pole piece has two
One end of the opposite side of the pole piece is formed in a linear shape, and the circle of the outer circumference do not face each other two of said pole pieces
An electromagnet for an electromagnetic contactor formed in an arc shape .