EP0910861A1

EP0910861A1 - Process for manufacturing an electromagnetic relay

Info

Publication number: EP0910861A1
Application number: EP97931620A
Authority: EP
Inventors: Josef Kern
Original assignee: Siemens AG
Current assignee: TE Connectivity Solutions GmbH
Priority date: 1996-07-10
Filing date: 1997-06-17
Publication date: 1999-04-28
Anticipated expiration: 2017-06-17
Also published as: WO1998001878A1; DE59701119D1; CN1225190A; CN1075237C; DE19627845C1; ATE189746T1; JP2000514234A; US6272734B1; EP0910861B1

Abstract

The relay is formed from two half-shells which are formed by extrusion coating the functional elements with plastic. A first half-shell is formed by extrusion coating a coil with a U-shaped core, while a second half-shell is formed by extrusion coating a spring support and at least one fixed contact element. A contact spring having a flat armature is attached to the spring support. The relay is adjusted and at the same time sealed by the process of joining the two half-shells.

Description

description

Method of manufacturing an electromagnetic relay

The invention relates to a method for producing an electromagnetic relay

- A coil penetrated by a core with a winding and with connecting pins, the core forming pole plates at both ends outside the coil, - An armature bridging the pole plates to form working air and

- A contact arrangement with a contact spring actuated by the armature and at least one fixed contact element interacting with the contact spring.

EP 0 531 890 AI describes a switching relay and a method for its production, the relay elements being arranged in the above-mentioned manner in a two-part housing. However, the two housing parts there do not form a closed housing, but are merely a base, which is preferably a printed circuit board with an integrally formed side wall, and a cover part, between which a housing gap remains open even after the assembly. The relay there is preferably designed as a multiple relay with a series of magnet systems lying next to one another, a common core pole plate lying on the base and forming a series of vertically projecting core sections, each of which is fitted with a coil. Each system also has a U-shaped armature, which is mounted on the core pole plate and encloses the coil in a frame shape with the contact spring. The cover part has slots with inserted mating contact elements and spring supports, these slots also not being tight. In general, a conventional manufacturing technique is used for the relay there, the individual elements being subsequently attached to one or the other housing part by plugging, riveting or in a similar manner. The aim of the present invention is an inexpensive manufacture of relays of the type mentioned for different sizes and applications. In this case, high manufacturing accuracies for the mechanical relay characteristic values are to be achieved without the need for a separate adjustment process.

According to the invention, this aim is achieved with a method which has the following steps:

- The coil provided with the core is embedded with its connecting pins to form a first housing half-shell in plastic;

- A spring support for the contact spring and at least one fixed contact element are embedded in plastic to form a second housing half-shell;

- The anchor is inserted in one of the two half-shells and

- The edges of the two half-shells are joined tightly together.

The manufacture of the relay housing according to the invention in the form of two half shells made of plastic, in which the functional elements are anchored by embedding, not only achieves a positionally accurate fixing of all parts, but also a simple and effective sealing of the housing, since the connecting elements of the relay are all already sealed off by the embedding and the edges of the two half-shells lie on one another only in the form of easily sealed plastic surfaces. Preferably, all parts are manufactured by injection molding or assembled. This achieves a high level of manufacturing accuracy, since the precise injection mold specifies the position tolerance of the individual parts. These individual parts are preferably made from flat sheet metal strips and overmolded in succession or simultaneously. This injection molding assembly is particularly well suited for a production by cycle Injection molding of parts connected on the belt, which means that large quantities can be manufactured at a reasonable price.

Refinements and developments of this general manufacturing process are specified in the subclaims.

The invention is explained in more detail below using exemplary embodiments with reference to the drawing. FIG. 1 shows a relay produced in accordance with the invention in a perspective, partially cut-open representation, FIG. 2 shows a sheet metal strip with partially cut-out core yoke sheets,

4 shows a sheet metal strip with bobbins that are partially wound, FIG. 5 shows a sheet metal strip from FIG. 4 with wound bobbins that are partially molded with plastic to form a first housing half-shell,

6 shows a separated first half-shell in a view rotated in relation to FIG. 5, FIG. 7 shows a finished second half-shell, FIG. 8 shows a contact sheet strip with partially punched-out fixed contact elements in two toothed rows, FIG. 9 shows a separated row of fixed contact elements connected to a sheet metal strip, FIG Formation of second half shells by overmolding of fixed contact elements and spring supports,

FIG. 11 shows a series of contact springs punched out on the band and provided with an anchor,

FIG. 12 shows a row of second housing half-shells connected to the belt, which are provided with a spring anchor unit,

FIG. 13 shows a modified form of a spring anchor unit, FIG. 14 shows a schematic illustration of a modified version of a housing half-shell in section in an injection mold,

FIG. 15 shows a relay completed by stacking two housing half-shells in a section through the armature,

16 shows a modified Aufefüh ^'approximate shape of a relay according to the invention in perspective view.

Figure 1 shows a relay manufactured with the inventive method. It consists of a first half-shell 1 and a second half-shell 2, the half-shell 1 being formed by overmolding a coil 3, namely a coil former 31 with a winding 34, and the second half-shell is formed by overmolding a spring support 21 and two fixed contact elements 22 and 23. An L-shaped contact spring 4 is fastened to the spring support 21 with two legs 41 and 42, which in turn carries an armature 5. The ends of the approximately Z-shaped armature 5 each form working air gaps with two pole faces 63 and 64 of two pole plates 61 and 62, which are part of a U-shaped core 6, the pole plate 62 being bent upward from the core plane .

The individual process steps for producing the relay of FIG. 1 are shown in the following figures. Thus, FIG. 2 shows the production of core yoke sheets 6, which are successively cut and bent from a soft magnetic sheet metal strip 60 in the production cycle. FIG. 3 shows the sheet metal strip 6 with the core yoke sheets 6 in a later process stage, but still in a continuous manner. The core yoke plates 6 are already overmolded with a thermoplastic, so that a coil former 31 is formed in such a way that the two pole plates 61 and 62 are free of plastic. In the bobbin 31 two pins 32 and 33 are also embedded, which are also related to a sheet metal strip 30. In this case, connection sections 32b and 33b are also saved in the coil former which are later contacted to the winding ends. It should be mentioned here that the coil connecting pins 32 and 33 on the one hand and the core yoke plate 6 on the other hand could also be produced from a common soft magnet sheet metal strip, the separation being able to be carried out in a corresponding manner after the extrusion coating.

In the further course, the coil former units formed by extrusion coating are separated on one side, for example from the sheet metal strip 60, so that they are only connected on one side, for example via the sheet metal strip 30 according to FIG. 4. In this state, they are gradually provided with the winding 34, the winding ends being connected to the terminal portions 32b and 33b.

Subsequently, the coil units according to FIG. 5 are gradually overmolded in the production cycle with a thermoplastic to form the half-shells 1, as shown in FIG. 5. These overmolded half-shells 1 are still connected via the metal strip 30. The individual half-shells are then separated from the sheet metal strip, and the cut-out coil connecting pins 32 and 33 are angled, as shown in another view in FIG. 6. The coil including the winding is now completely encased in the plastic of the first half-shell 1, only the pole faces of the pole sheets 61 and 62 being kept free from the plastic.

The second housing half-shell 2 of the relay is shown in FIG. 7 in the finished state. The following figures show individual process sections in their manufacture. 8 shows the extraction of fixed contact elements 22 and 23 from a sheet metal strip 20 which is plated with a central strip 20C made of contact material, for example AgNi015, AgSn0 ₂ or the like. The contact material layer 20C is plated as an inlay in the strip material 20 so that it does not form a surface increase, as a result of which the contact elements can be easily sealed in the injection mold. In order to save as much material as possible, the fixed contact elements 22 and 23 are cut out like a zipper from the inlaid band 20 so that the precious metal portion of the plated layer 20C is optimally used. In this way, two contact strips 20A and 20B are formed, one of which carries the normally open fixed contact elements 22 and the other the normally closed contact elements 23. FIG. 9 shows a contact strip 20A detached from the composite with the partially cut-off fixed contact elements 22 and their contact-making zone 22c.

As shown in FIG. 10, the mutually twisted contact strips 20A and 20C are extrusion-coated with the plastic material of the second half-shell 2, the plated sections 22c and 23c facing each other. Due to the asymmetrical design of the fixed contact elements 22 and 23, the contacting sections 22c and 23c lie one above the other, while their connecting ends 22a and 23a lie offset in the wall of the half-shell 2. When the half-shell 2 is sprayed, spring supports 21 are also injected, which are likewise connected to a common sheet-metal strip 10. The spring supports 21 each have a fastening tab 44 bent open at right angles for the contact spring, which will be described later.

The second half-shell forms a cavity for receiving the movable armature-spring unit 4, 5, which is shown in FIG. 11. 11a shows a spring band 40, from which the individual contact springs 4 are gradually cut free, bent and provided with the movable contacts 43 in the production cycle. Finally, the armature 5, which is also cut from sheet metal and pre-bent, is fastened to the contact spring, for example via a welding point 51. This armature-contact spring unit is then arranged in the second half-shell on the spring support 21 and fastened, for example, via a welding point 46 (FIG. 12) . The connection of the contact spring 4 to the armature 5 can, however, also be carried out by injection molding around with an insulating material sheath 52, as shown in FIG. In this way, electrical insulation between the contact spring 4 and the armature 5 or the magnet system is also achieved.

In the injection molding, the distance between the two flat contact strips 20A and 20B (FIG. 10) is achieved with the high accuracy of a slide in the tool, so that there is an adjustment-free contact position in the later relay. But it is also conceivable to work with an injection mold without an additional slide. For this purpose, the relay construction is arranged in the two half shells so that the contact surfaces are perpendicular in the second half shell. A corresponding arrangement is shown schematically in FIG. 14, where a lower half-shell 102 is formed between two mold halves 110 and 120. Two fixed contact elements 122 and 132 with corresponding inlay contact layers are arranged in this lower half-shell in such a way that they are perpendicular to the mold parting plane 130. A molded projection 111 gives the precisely specified contact distance a between the two fixed contact elements 122 and 132 and seals the contact area well, since the pressure of the thermoplastic injection molding compound 103 for the half-shell 102 presses the two fixed contact elements 122 and 132 against this spacing projection.

When joining the two half-shells 1 and 2 according to FIG. 15, a peripheral wall 12 of the half-shell 1 engages in a box-like manner over the half-shell 2, which for this purpose has a web 24 which runs around the inside. In order to achieve a precise adjustment of the distances between the magnet system and the contact system, one of the half-shells also has a circumferential rib 25 which is deformed during the joining, for example by means of ultrasound, and creates a tight connection between the two half-shells. Sealing is very easy in this way, as all connections have been made beforehand are overmolded in the respective half-shell and the joining plane is formed by thermoplastic plastic of the two half-shells. When the two half-shells are joined, the pull-through voltage of the armature is measured, the armature being attracted to the pole faces 63 and 64 of the pole plates 61 and 62. As soon as a predetermined characteristic value of the pull-through voltage as a measure of the erosion size or the overstroke of the contact is reached, the joining process is ended. The relay is adjusted and sealed at the same time. The joint seam on one level without a height difference ensures that the two half-shells can be securely sealed, but also with other technologies, for example by gluing, clamping, casting or using an elastomer seal that can be molded onto a half-shell using the two-component injection molding process.

In Figures 1 and 15, the pins of the relay are arranged on two opposite sides of the housing and bent downwards at right angles. In this way, they can be used as solder pins or can also be used as SMT connectors by further bending them horizontally. With a corresponding modification of the construction, however, a different connection geometry is also possible, so that, if necessary, all connection elements emerge on one housing side. These can of course be designed both as solder pins and as flat tabs.

A variant of the relay is shown in FIG. 16, with all connections emerging from the housing on only one side and the parting plane extending perpendicularly to the connection side of the relay. In this case too, a first half-shell 201 contains the magnet system with coil pins 232 and 233, while the second half-shell 202 carries the contact system with contact pins 221, 222 and 223. In this case too, the two half-shells are joined together along a parting plane 203, with a corresponding one also here Construction can be done by assembling an adjustment.

Claims

claims

1. A method for producing an electromagnetic relay with - a coil (31, 34) with a core (3) interspersed with a winding (34) and with connecting pins (32, 33), the core (3) at both ends outside the Forms coil plate (61,62),

- An armature (5) bridging the pole plates (61, 62) to form working air gaps and

- A contact arrangement with a contact spring (4) actuated by the armature and at least one fixed contact element interacting with the contact spring, characterized by the following steps: - The coil (31, 34) provided with the core (3) is connected with its connecting pins (32, 33) embedded in plastic to form a first housing half-shell (1),

a spring support (21) for the contact spring (4) and at least one fixed contact element (22, 23) are embedded in plastic to form a second housing half-shell,

- The anchor (5) is inserted into one of the two half-shells (2) and

- The two half-shells (1,2) with their edges

(12,24) tightly connected to each other.

2. The method according to claim 1, characterized in that 'first a core (6) cut out of sheet metal (60) and also from a sheet metal (30) cut out coil connecting pins (32, 33) are molded to form a coil former (31) with plastic are formed, at the ends of the core (6) formed pole plates (61, 62) remain free, and that the coil former (31) is then wound.

3. The method according to claim 2, d a d u r c h g e k e n n z e i c h n e t that the cores (6) and coil connecting pins (32,33) for a plurality of relays are extrusion-coated on their metal strip (60; 30) connected in the manufacturing cycle

4 The method of claim 3, d a d u r c h g e k e n n z e i c h n e t that several coil formers (31) are wound hanging on the common sheet metal strip (30).

5 The method according to claim 4, so that several coils (31, 34) on the common sheet metal strip (30) are revolved in the production cycle to form the first half-shell (1).

6. The method according to any one of claims 2 to 5, that the cores (6) and the coil connection pins (32, 33) are made of the same thing

Cut metal strips (60), overmolded together and subsequently separated.

7. The method according to any one of claims 1 to 6, characterized in that for producing the second half-shell (2) each have a spring support (21) hanging on the belt (10) and at least one fixed contact element (22) also hanging on a belt (20A, 20B) , 23) are encapsulated with plastic.

8. The method according to claim 7, so that a sheet-metal strip (20) is coated along a central section (20C) with contact material in order to produce the fixed contact elements (22, 23) and then the individual

Fixed contact elements (22, 23) are cut alternately in opposite directions so that their contact The ends (22c, 23c), which abut one another like a zipper, encompass part of the central section (20C), while their connection ends (22a, 23a) alternately remain connected to one of two remaining fixed contact strips (22, 23).

9. The method according to claim 8, characterized in that the fixed contact elements (22,23) are each formed in the sheet metal plane with their contacting region (22b, 23b) asymmetrically with respect to the axis of their connecting ends (22a, 23a) and that in the manufacture of the second Half-shell (2) with two fixed contact elements (22, 23), two fixed contact strips (20A, 20B) at an angle to one another so that the contacting sections (22b, 23b) face each other with their coated sides and the connection ends (22a , 23a) are mutually offset in parallel.

10 Method according to one of claims 1 to 9, d a d u r c h g e k e n n z e i c h n e t that during the injection molding of the second half-shell (2) the distance (a) between two fixed contact elements (122,132) by an element (111) of the injection mold (110,120) is exactly defined

11. The method according to any one of claims 1 to 10, so that the armature stroke and / or the excess stroke are measured when the two half-shells (1, 2) are joined and the joining process is ended when a predetermined size is reached.

12. The method according to claim 11, characterized in that the edge or a rib (25) formed on the edge of at least one of the two half-shells (1) is deformed during joining until the predetermined anchor stroke or overstroke is reached.

13. The method of claim 12, d a d u r c h g e k e n n z e i c h n e t that the edge or the rib (25) of a half-shell is deformed by ultrasound when joining.