Patent Application
20100060396
The invention relates an electromagnetic relay and in particular to a coil former and a coil body of an electromagnetic relay.
In order to achieve a particularly simple manufacturing process and compact construction in electromagnetic relays, it is known for the base and the coil former of such an electromagnetic relay to be produced from a plastic material in a one piece construction. DE 19718985 C1 shows, for example, a relay having a combined coil body of this type. The relay, disclosed, consists of a coil former, a T-shaped or almost M-shaped core, a U-shaped armature, a card-shaped slider, a fixed contact spring, a mobile contact spring, a casing and two coil terminals fixed in the coil former. The double plate which comprises receiving slots for the connector elements of the contact springs is integrally molded on the coil former.
A further known configuration of a relay with a coil body of this type is known from EP 1 271593 A2. There is a decisive drawback, however, with this known configuration during production. That is to say, generally by means of an injection-molding process, it is always necessary to have four demolding directions. This is based on the fact that the known coil bodies correspondingly include many undercuts. Of course, this also applies to known coil formers, which are produced separately without the base. In addition, the required master mold tools for producing such a coil former or coil body are comparatively expensive, and the production method is correspondingly lengthy, in particular with regard to demolding process.
Combined coil bodies generally include a base and a coil former which are produced in one piece and of which the longitudinal axes extend substantially transversely to one another. The flanges required for fixing the coil winding are conventionally produced, on the one hand, in an end region of the coil former and, on the other hand, are formed so as to be integrated by a corresponding face of the base (see, for example,
An object of the present invention, among others, is to improve a coil former for an electromagnetic relay so the coil body can be produced more quickly and in a more cost-effective manner.
The coil former for an electromagnetic relay includes a first coil flange, a second coil flange, and a cylindrical winding area for fixing a coil winding. The cylindrical winding area is arranged between the first and second coil flange. At least one of the coil flanges is shaped such that at least a portion of one coil flange is flush with the winding area of the coil former in a region of a periphery of the coil former.
The present invention will be described in detail in the following based on the figures enclosed with the application, of which:
For an improved understanding of the invention, it will now be described in more detail with the aid of the embodiments shown in the following figures.
With reference to
In the embodiment shown, the first coil flange 108 does not occupy the entire periphery of the winding area 116. Rather, the first coil flange 108, according to the invention, is arranged along three peripheral sides of the winding area 116, and is omitted from the fourth side of a rectangular cross-section thereof. Because the first coil flange 108 is flush with the winding area 116 along the fourth side of a rectangular cross-section, an outer side of the coil former 104 may be demolded at this face in the same direction as the interior 113. In this embodiment, the second coil flange 110 is integrated with a base 106 (see
In particular, the construction of the coil former 104, according to the invention, has a particularly advantageous effect with regard to injection molding, which is characterized in that plasticized material, such as a thermoplastic polymer, is injected into a cooled master mold tool (the injection-molding tool) at a high pressure. In the case of thermosets, the plasticized material is injected into a heated master mold tool at a high pressure and solidifies under the influence of pressure. After the plasticized material has solidified, the injection-molding tool is opened and the molded part is removed. Opening the injection-molding tool is a multiple-stage process, of which the complexity depends on the number of undercuts in the molding. In the embodiment shown, the coil former is prepared from an electrically insulating material, and manufactured using injection molding. However, other plasticized materials and manufacturing methods are possible, as long as a portion of the coil former 104 is prepared having a first coil flange 108 that is flush with the winding area 116. Therefore, the production method allows for the outer side of the coil former 104 to be demolded along this face in the same direction as the interior 113.
In principle, the first coil flange 108 may not necessarily be provided with the coil former 104, in order to reliably fix and hold the coil winding 124 (see
With reference to
At a free end of the coil former 104 a collar is arranged so as to form a first coil flange 108. A second coil flange 110 is produced by a corresponding flange region of the base 106, i.e. a surface portion of the base 106. Accordingly, a longitudinal axis of the coil former 104 corresponds to a winding coil axis and extends substantially transversely to a longitudinal axis of the base 106.
Receiving slots 112, for inserting contact springs, of a contact system are provided in the base 106. Openings 114 are formed in the second coil flange 110 and are used for fixing coil terminals 115, i.e. coil connector pins (see
According to the invention, the first coil flange 108, between which the coil winding 124 (see
The first coil flange 108, formed as a partial flange, is adequate for securely fixing and holding the coil winding 124 (see
According to the invention, the first coil flange 108, minimized in such a way that the fourth side of the cross-section, along a periphery of the winding area 116, remains free, allows the coil body 102 to be demolded in a substantially simplified manner. Furthermore, the production of the coil body 102 is simplified, and allows for a simplified tool. In particular, the coil body 102, of this type, may be advantageously used in the particular field of electromagnetic relays.
The invention is therefore based on the idea that one of the two coil flanges 108, 110 of the coil former 104 are configured in such a way that a portion of one coil flange (i.e. the first coil flange 108), specifically the periphery, sits flush with the winding area 116. An omission of this portion of one of the two coil flanges 108, 110 allows the outer side of the coil former 104 to be demolded in the same direction as the core 126. In this manner, it is possible to construct undercuts of a coil former 104, in such a way, that a minimum number of demolding directions may be provided, even only two in an appropriate construction. This reduces the complexity of the master mold and accelerates demolding during the production process. For an integrated coil body 102, which has such a coil former 104 with an integral base 106, reduction of necessary demolding directions may be performed in an advantageous manner according to the invention.
As shown in
The core 126 is inserted into the coil former 104 and arranged in such a way that a yoke 128 can cooperate with an armature 140. The coil winding 124 is supplied with current via the coil terminals 115. A fixed contact 132 and a moveable contact 130 are arranged in the receiving slots 112 (see
When the current flows, the armature 140 is attracted to the yoke 128 and the moveable contact spring 130 is pressed onto the fixed contact 132 via a slider 134, which may occasionally also be referred to as a ridge, and electrical contact is produced.
A casing 136 protects the electromagnetic relay 100 from dust and disruptive environmental influences. However, by removing a protruding lug 138, the relay may be ventilated if desired.
According to another embodiment of the present invention, the coil former 104, with only two demolding directions, may be produced in that one of two coil flanges 108, 110 may be integrally molded on an end region of the coil former 104 does not occupy the entire periphery, but is only present at approximately less than three quarters of the periphery. A part of the periphery of the coil former 104, facing the region of the base 106, in which part the contacts 130, 132 are arranged, is configured without an undercut so no coil flange is provided there. In this manner, the master mold can be removed from the finished coil former 104 in only two demolding directions.
The present invention is therefore based on the idea that in order to reliably fix and hold the coil winding 124, it is not necessary for the first coil flange 108 to be circumferential. This basic principle may of course also be used for any type of coil which includes a coil former 104 with a coil winding 124 wound thereupon.
While the embodiments of the present invention have been illustrated in detail, it should be apparent that modifications and adaptations to those embodiments may occur. The scope of the invention is therefore limited only by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2007 024 128.5 | May 2007 | DE | national |
This application is a continuation of PCT International Application No. PCT/EP2008/003769, filed May 9, 2008, which claims priority under 35 U.S.C. §119 to German Patent Application No. DE 10 2007 024 128.5, filed May 24, 2007.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2008/003769 | May 2008 | US |
| Child | 12621919 | US |
