JPH0136216B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses an E-shaped fixed core in which an electromagnetic coil is inserted in the central leg and a hinged movable iron piece, and the fulcrum of the movable iron piece is configured on one outer leg of the fixed iron core. The present invention relates to a contactor, and relates to preventing movement of a movable iron piece during polarization by effectively utilizing magnetic flux generated by an electromagnetic coil.

Conventionally, there have been methods for suppressing the movement of the movable core of an electromagnetic contactor when the movable core is connected, such as attaching a leaf spring or rubber plate to the bottom of the fixed core, or providing a buffer mechanism using a coil spring, etc. The method is
This requires space to install the leaf spring, rubber plate, and buffer mechanism, and has the disadvantage that the external dimensions of the electromagnetic contactor become large. In addition, in Utility Model No. 55-18913,
A configuration in which a groove is provided in the bent part of a movable iron piece that has been bent into a shape is disclosed, but when increasing the magnetic resistance on the fulcrum side with such a configuration, the magnetic resistance will be increased due to the relationship with the mechanical strength of the movable iron piece. It is impossible to set to any value. In addition, the grooves reduce the mechanical strength of the movable iron piece, making it more likely to twist during machining, making it impossible to obtain flatness, resulting in buzzing, and stress concentration tends to occur in the grooves, shortening the opening/closing life. There is a problem with becoming. Further, since the iron pieces come into direct contact with each other at the fulcrum portion, iron powder is likely to be generated due to wear, and this tends to adhere to the armature surface, resulting in a problem in that the reliability of the product is likely to deteriorate.

The purpose of the present invention is to suppress the movement of the movable iron core when the movable iron core is poled without using a buffer mechanism using a rubber plate, leaf spring, coil spring, etc., and to improve the mechanical strength of the movable iron piece and the reliability of the product. An object of the present invention is to provide an electromagnetic contactor that is excellent in performance and can be downsized.

Conventional methods using leaf springs, rubber plates, and buffer mechanisms are methods that reduce the collision force when the movable core is polarized, thereby suppressing the separation force of the movable core from the fixed core and preventing the movable core from moving. However, the present invention focuses on the fact that in an electromagnetic contactor using a hinged movable iron piece and an E-shaped fixed core, the collision force when the movable iron piece is connected is generated on the side opposite to the fulcrum (on the side opposite to the fulcrum). The attraction force between the movable iron piece and the fixed iron core is almost unchanged until the iron piece is connected to the opposite fulcrum side, but the attraction force on the opposite fulcrum side is increased when the movable iron piece is connected, so that the attraction is greater than the opening force after the moving iron piece is connected. Force is generated between the movable iron piece and the fixed iron core to suppress the movement of the movable iron piece.

Hereinafter, the first embodiment of the present invention will be explained in FIG. 1, FIG.
This will be explained with reference to FIG. For comparison, FIG. 3 shows a conventional example corresponding to FIG. 1. In FIG. 1, 1 is a bottom-opening case with a fixed contact 2 attached to the upper part, 3 is a movable contact that is pressed and attached to a movable insulating table 4 by a contact spring 5 at a position corresponding to the fixed contact, and 6 is a case with a lower opening. Convex portion 4' provided on insulating table 4
and a return spring biased between the fixed core 7 and the case 1; 7 is an E-shaped fixed core with an electromagnetic coil 8 inserted into the central leg; 9 is an L-shaped movable piece of iron; It has a surface portion 11 that comes into contact with the tip of the movable insulating table 4. In addition, one end (right side in the figure) of the surface portion 10 of the movable iron piece 9 corresponding to the fixed iron core 7 corresponds to the one outer leg end face angle 12 of the fixed iron core 7, and a thin non-magnetic plate 13 attached to this portion (painted) is engaged with the outer leg end face corner 12. 14 is an insulating plate that separates the contact portion and the electromagnet portion, and 15 is a bottom plate that closes the lower opening of the case 1.

When the electromagnetic coil 8 is not energized, the return spring 6 presses the movable insulating base 4 to the right in FIG. Movable iron piece 9 in contact with
The surface portion 11 of the movable iron piece 9 is pushed to the right in FIG.
The movable iron piece 9 and the fixed iron piece 7 are opened at the position where the tip of the face part 10 of the movable iron piece 9 comes into contact with the insulating plate 14 by pivoting about the corresponding engagement part of the one outer leg end face corner 12 of the fixed iron core 7 of the face part 10 of Retain state. When the electromagnetic coil 8 is excited, an attractive force is generated between the movable iron piece 9 and the fixed iron core 7, and the movable iron piece 9 moves the engaging portion of the movable iron piece 9 and the fixed iron core 7 in the direction of the fixed iron core 7 against the intersection point. Rotating clockwise, the movable insulating base 4 is pushed by the face 10 of the movable iron piece and moves to the left in FIG. 1, closing the contact.

In FIGS. 2 and 3, 9 is an electromagnetic coil 8
indicates the movable iron piece when it is not energized, and 9' shows the movable iron piece when the electromagnetic coil 8 is energized and is in contact with the fixed iron core 7. Reference numeral 19 denotes a fulcrum part outer leg 18 of the E-type fixed iron core 7, which is the fulcrum of the manual iron piece 9, which is an outer leg of the armature surface of the E-type fixed iron core on the armature side of the movable iron piece 9.
0 is the central leg of the E-shaped fixed core into which the electromagnetic coil 8 is inserted. Movable iron pieces 9, 9' and E type fixed iron core 7
A magnetic circuit (fulcrum magnetic circuit) consisting of the fulcrum outer leg 19, center leg 20, movable iron pieces 9, 9' of the fixed iron core 7, and the armature outer leg of the fixed iron core 7. 18, central leg 20, movable iron piece 9, 9'
In the case of FIG. 3 without a non-magnetic thin plate, the movable iron piece 9 is polarized to the fixed iron core 7 after the electromagnetic coil 8 is excited. Until now, the magnetic resistance of the magnetic circuit on the armature side was larger than the magnetic resistance of the magnetic circuit on the fulcrum side, and therefore the magnetic flux generated by the electromagnetic coil would pass through the magnetic circuit on the fulcrum side, and the movable iron piece 9' When the fixed iron core 7 is connected, the magnetic resistances of both magnetic circuits are equal, and the magnetic flux generated by the electromagnetic coil is equally divided between the two magnetic circuits.
In the case of FIG. 2 in which the non-magnetic thin plate 13 of this embodiment is provided on the surface of the fulcrum outer leg 19 of the E-shaped fixed core 7, if the thickness of the non-magnetic thin plate is t, then the outside of the armature surface of the fixed iron core 7 is When the distance l between the leg 18 and the movable iron piece 9 is approximately equal to t (just before the armature), the magnetic resistances of the armature surface magnetic circuit and the fulcrum magnetic circuit become equal, and before that, the magnetic resistance of the fulcrum magnetic circuit is After that, the magnetic resistance of the armature surface magnetic circuit becomes smaller, and from just before the armature of the armature surface outer leg 18 of the movable iron piece 9 and the fixed iron core 7 to the armature, the magnetic flux due to the electromagnetic coil 8 is less than the fulcrum section magnetic circuit. Also passes through many magnetic circuits on the armature surface. Therefore, the attractive force F between the movable iron piece 9 and the armature outer leg 18 of the fixed iron core 7 is larger than the attractive force F' in the case where the non-magnetic thin plate 13 is not provided.

That is, in Fig. 5, if the magnetic fluxes passing through the magnetic circuit on the fulcrum side of the movable iron piece are B and B', and the magnetic fluxes passing through the magnetic circuit on the armature side of the movable iron piece are A and A', then in Fig. 2, the magnetic flux of the conventional product is If there is no non-magnetic thin plate, the movable iron piece 19
Until it contacts the fixed iron core 7, (magnetic resistance of the polarization side magnetic circuit)>(magnetic resistance of the fulcrum side magnetic circuit), and the magnetic fluxes of both circuits become A'<B'.

When a non-magnetic thin plate 13 is provided at the fulcrum, when the distance l between the fixed iron core 7 and the movable iron piece 9 is equal to the thickness t of the thin plate 13 (l=t), the magnetic resistances of both magnetic circuits are equal and both It becomes equal to the magnetic fluxes A and B passing through the magnetic circuit. As l becomes smaller than t, the magnetic resistance of the armature side magnetic circuit becomes smaller due to the magnetic resistance of the fulcrum side magnetic circuit, and the relationship between the magnetic fluxes of both circuits is A
>B, and when the armature is in contact, a magnetic flux equal to the magnetic flux reduction amount △B of the fulcrum side circuit passes through the armature side circuit, and the armature side magnetic flux A is △A ( = △B) increases. In Figure 5, the attraction force on the armature side of the E-type fixed iron core 7 near the armature is shown.
When PA is the suction force on the fulcrum side and PB is the suction force on the movable insulating base of the movable iron piece 3 due to both suction forces,
FA and FB become FA=a/bPA and FB=a'/bPB. Here, a≫a′, a>b, a′<b, so FA≫
FB, and due to the increase in the magnetic flux of the magnetic circuit on the armature side of the fixed iron core, as shown in Fig. 4, the movable insulating table pressing force F of this embodiment is such that there is no non-magnetic thin plate 4 after the armature vicinity (l≒t). It is larger than the movable insulating table pressing force F' in the case of the maximum △F, that is, F ₀ in Fig. 4.
The difference between and F′ ₀ increases.

As described above, in this embodiment, a non-magnetic thin plate is provided on the fulcrum side, and the magnetic resistance of the fulcrum side magnetic circuit of the parallel magnetic circuit composed of the E-type fixed iron core 7 and the movable iron piece 9 is changed to the magnetic resistance of the fulcrum side magnetic circuit. By making the magnetic flux larger than the magnetic resistance and making the magnetic flux near the armature on the armature side larger than that on the fulcrum side, it acts to reduce the movement of the movable iron piece 9 when it is poled. The thickness of the non-magnetic thin plate is set to 0.5 mm in order to prevent increase in electromagnet loss due to increase in current and saturation of magnetic flux on the armature side.
It is better if it is below that level. In addition, since the collision force of the armature of the movable iron piece with the fixed iron core is influenced by the attraction force immediately before the armature, in the above embodiment, it hardly increases compared to the conventional one, and the force that tries to move hardly increases. .

According to this embodiment, when the movable iron piece 9 is polarized, the armature surface outer leg 1 of the fixed iron core 7 from just before the polarization to the time of polarization.
Since the suction force between the movable iron piece 9 and the movable iron piece 9 can be increased, the force of collision of the movable iron piece 9 against the outer leg 18 of the armature surface is hardly increased, and the suction force that counters the separation force of the movable iron piece 9 after the armature is created can be increased. The force can be increased and the movement of the movable iron piece 9 can be suppressed. In this embodiment, an arbitrary magnetic resistance can be obtained by changing the thickness of the non-magnetic thin plate 4. As the non-magnetic thin plate 4, a copper-based metal plate such as phosphor bronze is generally used. Further, in this embodiment, since the magnetic resistance on the fulcrum side of the movable iron piece 9 is increased by the non-magnetic thin plate 4, it is not necessary to form a groove in the movable iron piece 9, and the movable iron piece 9 has excellent mechanical strength. can be used to prevent the movable iron piece from breaking due to stress concentration, and also to easily obtain flatness and prevent the occurrence of beats. In addition, since the fulcrum part contacts the fixed iron core 7 through the non-magnetic thin plate 4, it is possible to prevent the generation of iron powder due to wear of the movable iron piece 9, and improve reliability as iron powder does not adhere to the armature surface. can be done. Note that even when the non-magnetic thin plate 4 is worn, non-magnetic powder is generated, so that it is not attracted to the adhesive surface by the magnetic force of the fixed iron core 7.

In the present invention, the attraction force between the movable iron piece and the outer leg of the fixed iron core on the earthing side increases from just before the movable iron piece is polarized to when the movable iron piece is polarized, so the collision force when the movable iron piece is polarized is increased. It is possible to increase the suction force that opposes the separation force after contacting the electrodes.

According to the present invention, it is possible to suppress the movement of the movable iron piece, thereby reducing the size of the movable iron piece by eliminating the need for mounting space for a buffer mechanism, and also to improve the mechanical strength of the movable iron piece by preventing destruction of the movable iron piece due to concentration of stress. In addition, the fulcrum of the movable iron piece contacts the fixed iron core through a non-magnetic thin plate, which prevents wear on the movable iron piece and prevents iron powder from adhering to the armature surface, resulting in highly reliable electromagnetic You can get a contactor.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the electromagnetic contactor according to the first embodiment of the present invention, Fig. 2 is an enlarged view of the electromagnet part of the electromagnetic contactor according to the embodiment of the present invention, and Fig. 3 is an enlarged view of the electromagnet part without a non-magnetic thin plate. Figure 4 shows the relationship between the attractive force and the distance between the movable iron piece and the outer leg of the armature surface of the fixed iron core, and Figure 5 shows the magnetic flux path in Figure 2. FIG. 6 is a diagram showing changes in magnetic flux in each path. 7; E type fixed iron core, 8; Electromagnetic coil, 9; Movable iron piece before armature, 9'; Movable iron piece after armature, 1
3; non-magnetic thin plate, 18; armature outer leg, 19; fulcrum outer leg, 20; center leg, l, l'; distance between movable iron piece and armature outer leg, t; non-magnetic thin plate Thickness, F,
F′; Attraction force between the movable iron piece and the outer leg of the armature, F ₀ , F′ ₀ ;
Attraction force when connected to the above.

Claims (1)

[Claims] 1. A fixed iron core having an E-shaped leg in which an electromagnetic coil is inserted into the central leg, and a hinged movable iron piece provided so that one outer leg of the fixed iron core is on the rotation fulcrum side and the other leg is on the polarization side. The electromagnetic contactor comprising: a non-magnetic thin plate disposed to be interposed between the fulcrum side of the movable iron piece and a surface of one outer leg of the fixed iron core facing the movable iron piece; An electromagnetic contactor characterized in that, when the iron piece is polarized, the fulcrum side of the iron piece is polarized to the fixed iron core via the non-magnetic thin plate, and the polarized side of the iron piece is configured to be directly polarized to the fixed iron core.