JPH0810944Y2 - electromagnet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an electromagnet used for a relay or the like.

[Conventional technology]

A conventional electromagnet is composed of a coil frame having a body around which a coil is wound, an iron core inserted into the coil frame, a permanent magnet and a yoke.

As shown in FIG. 5, the coil frame a includes a body portion b having a substantially square cross section, outwardly facing flanges c formed at both ends thereof, and leg portions d, and the coil portion a is An exciting coil e is wound around the outer circumference. The coil frame a is formed by injection molding with an insulator such as a synthetic resin material.

[Problems to be solved by the device]

When it is necessary to reduce the size of conventional electromagnets, such as when using them for ultra-small relays, etc., it is necessary to improve the attractive force as much as possible within the limited size. It is necessary to increase the number of turns of the excitation coil. To increase the number of turns,
In the case of a coil frame of a molded product, it is necessary to reduce the thickness of the body (cylindrical portion) or reduce the thickness of the body.

However, in that case, in the injection molding process of the coil frame, the core is inserted into the body portion of the molding die, but the core collapses due to the injection pressure of the molten resin, causing an uneven thickness portion, or the wall thickness is too thin. And a short shot (a phenomenon in which a thin portion or a small hole portion is formed due to the unfilled state) occurs, the coil frame cannot be accurately molded, and there is a problem that the insulation resistance decreases.

The present invention is intended to be improved by paying attention to the above-mentioned problems, and an object of the present invention is to achieve stable molding without uneven thickness portion in a body portion of a coil frame and to provide insulation resistance. It is to provide an ultra-compact electromagnet with high cost.

[Means for solving the problem]

In the electromagnet according to claim (1), the through hole is provided in the body of the coil frame, and the insulating coating is provided on the outer surface of the iron core inserted into the body.

In the electromagnet according to claim (2), the iron core is movable, and the outer surface thereof is provided with an insulating coating having high wear resistance such as Teflon, parylene, or polyimide resin.

[Action]

In the electromagnet of claim (1), when the coil frame is formed, the support pin is inserted into the through hole formed in the coil frame body to support the die core of the body, thereby preventing the core from collapsing.
Moreover, since the gas generated at the time of molding escapes from the through hole to the outside, the short shot due to the gas pressure is prevented, and the coil frame with no uneven thickness in the body can be obtained accurately.

In the electromagnet according to claim (2), by forming an insulating coating having wear resistance on the outer surface of the movable iron core, not only the insulation resistance is improved, but also the high resistance of the magnetic pole surface of the iron core and the hinge supporting portion is achieved. Wearability can be obtained and stable operation characteristics can be obtained.

〔Example〕

An embodiment of the invention will be described below with reference to FIGS.

As shown in FIG. 4, the relay using the electromagnet of the present invention includes an electromagnet 4 including a coil block 1, a yoke 2 and a movable iron core 3, a magnetic pole plate 5, a permanent magnet 6, a card 7, a contact block 8 and these. It is composed of a base 9 and a cover 10 to which is attached. A terminal pin 11 penetrates and is fixed to the base 9, and an inert gas such as nitrogen is sealed inside the cover 10 and the base 9.

As shown in FIG. 1 and FIG. 2, the coil block 1 has a substantially rectangular tubular body made of a molding material such as synthetic resin.
The coil frame 12 has a coil 12a, and a coil 13 wound around the outer circumference of the body 12a. A through hole 14 is formed at the center of the body 12a in the longitudinal direction, and flanges 12b are integrally provided at both ends in the longitudinal direction. As shown in FIG. 4, one of the collar portions 12b is
The yoke 2 made of a magnetic material is fixed.

As shown in FIG. 3, the through hole 14 of the coil frame 12 is located at a proper position in the hollow portion of the mold 16 during injection molding.
It is formed as a hole for a support pin 17 for fixing the core 15 forming 12a.

By supporting the core 15 with the support pins 17, it is possible to prevent the core 15 from falling down due to the injection pressure, and thus the body 12
It is possible to achieve a uniform thickness without uneven thickness in a. In the case of an ultra-small electromagnet, this coil frame 12 has a length of 10 mm or less, and the hole of the body 12a is also extremely small at 1 to 1.5 mm square,
Since the thickness of the molding core 15 is naturally thin, the injection pressure of the molten resin causes the core 15 to easily fall down,
By supporting with the support pin 17, it is possible to prevent falling and to prevent gas generated during molding from escaping from the gap between the support pin 17 and the pin hole 16a of the die 16, thereby preventing short shot from occurring, and the coil frame body 12a. Can be formed to have a uniform thickness.

The upper end of the yoke 2 is bent horizontally so that the movable iron core 3
And the one end supporting portion 3a of the movable iron core 3 is supported via a hinge spring 18 so as to be vertically swingable.

Further, the movable iron core 3 is integrally formed with an insulating material having a high wear resistance on the entire surface, for example, a coating film of Teflon, parylene, polyimide or the like, and is provided with insulation resistance and wear resistance. High wear resistance of the surface 3b and the hinge support portion 3a is obtained, and high electrical insulation between the coil 13 and the movable iron core 3 is obtained.

Therefore, it is possible to cover the deterioration of the insulating property due to the provision of the through hole 14 of the body portion 12a.

The insulating film formed on the outer surface of the movable iron core 3 is
The material is not limited to a material having high wear resistance, and may be at least insulation resistant.

The permanent magnet 6 is sandwiched between the upper and lower magnetic pole plates 5, and the magnetic pole surface 3b of the movable iron core 3 is positioned between the both magnetic pole plates 5 so as to be integrally attached to the base 9 via the holding body 19. Has been done.

The card 7 is made of an insulating material and has an upper end fixed to the movable iron core 3 so as to move up and down, and a movable contact spring 8a of a contact block 8 is engaged with the lower portion. The contact block 8 is composed of the movable contact spring 8a and fixed contacts 8b and 8c arranged above and below the free end of the spring 8a. The contact block 8 is attached to the base 9 via a holding body 19, and the terminal pin 11 It is connected together with.

Now, when the coil 13 is energized from one direction, the movable iron core 3
The free end moves upward, the upper magnetic pole surface 3b is attracted to the upper magnetic pole plate 5, and the movable contact spring 8a is driven upward via the card 7 to abut the upper fixed contact 8b. The permanent magnet 6 maintains the same state even when the excitation of the coil 13 is stopped.

When the exciting direction of the coil 13 is reversed, the movable iron core 3 is reversed so that its free end is attracted to the lower magnetic pole plate 5, and the movable contact spring 8a is driven downward via the card 7. And contacts the lower fixed contact 8c. The coil 13
This is a so-called bistable relay in which the same state is maintained by the magnetic flux of the permanent magnets 6 even when the excitation of (1) is stopped.

Although the movable iron core 3 is inserted into the coil frame 12 in the above-described embodiment, it is needless to say that the movable iron core 3 can also be adopted in an electromagnet of a type in which a fixed iron core (including a yoke) is inserted.
Also, the through holes 14 of the coil frame moving part 12a can be provided on four surfaces from two directions.

[Effect of device]

In the electromagnet of claim (1), when the coil frame is formed, the support pin is inserted into the through hole formed in the coil frame body to support the die core of the body, thereby preventing the core from collapsing.
Moreover, since the gas generated during molding escapes from the through holes to the outside, short shots due to gas pressure are prevented, uneven thickness of the body is prevented, uniform wall thickness is achieved, and a stable wall thickness is obtained. Therefore, it is possible to reduce the thickness while keeping the insulation resistance high, and to reduce the size.

In the electromagnet according to claim (2), by forming an insulating coating having wear resistance on the outer surface of the movable iron core, not only the insulation resistance is improved, but also the high resistance of the magnetic pole surface of the iron core and the hinge supporting portion is achieved. Wearability can be obtained and stable operation characteristics can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is a front view of the same as above, FIG. 3 is an explanatory view of a state in which a through hole provided in a body portion of a coil frame is used, and FIG. FIG. 5 is a partially cutaway front view of a relay using a devised electromagnet, and FIG. 5 is a perspective view showing a main part of a conventional example. 3 ... iron core, 4 ... electromagnet, 12 ... coil frame, 12a ...
Body, 13 ... Coil, 14 ... Through hole.

Claims (2)

[Scope of utility model registration request] 1. An electromagnet having a coil frame having a body around which a coil is wound, and an iron core inserted in the body, wherein a through hole is provided in the body of the coil frame and An electromagnet, comprising an insulating coating provided on an outer surface of an iron core that is inserted into the electromagnet. 2. The iron core is movable, and an insulating coating having high wear resistance is provided on the outer surface of the iron core.
Electromagnet.