EP0897586A1

EP0897586A1 - Electromagnetic relay

Info

Publication number: EP0897586A1
Application number: EP97925825A
Authority: EP
Inventors: Alfred Heinzl; Heinz Stadler
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 1996-05-07
Filing date: 1997-04-24
Publication date: 1999-02-24
Anticipated expiration: 2017-04-24
Also published as: CN1217814A; JP2000509548A; EP0897586B1; WO1997042643A1; CN1129939C; DE59700564D1

Abstract

A relay has a base with a bottom plate (2) which is part of a closed housing. Fixed contact elements (4) are anchored in the base. The fixed contact (7) carrying sections (6) of the contact elements (4) are arranged on the bottom plate, parallel thereto. An outwardly open recess (8) is provided in the bottom plate below each contact carrying section (6). The contact carrying sections (6) are cantilevered over said recesses. These recesses make it possible to adjust the contact carrying sections (6) even after the housing is sealed; they may be subsequently filled with glue.

Description

description

Electromagnetic relay

The invention relates to an electromagnetic relay

with a base made of insulating material, which defines a base plane with a base plate and which is part of a closed housing,

with fixed contact elements anchored in the base, each of which has a connecting lug which leads to the outside of the housing and a contact carrier section which is clamped on one side in the interior of the housing and extends cantilevered parallel to the base plane,

with at least one contact spring which interacts with a contact carrier section and is also connected to a connecting lug leading to the outside of the housing, and

- With an electromagnet system with coil, core and armature arranged above the base in the housing for actuating the at least one movable contact spring.

Systems of this type with fixed contact elements arranged in the base region are used, for example, in miniature relays, the contact springs being connected directly to a rocker arm, which in turn is actuated by a preferably polarized magnet system. Since very small contact distances are provided for such relays for low-current applications, these must also be set with very tight tolerances during production. For example, EP-A-0 423 834 discloses a relay of the type mentioned, in which the fixed contact elements are anchored in a base in such a way that the contact carrier sections initially emerge freely on the end faces of the base. In this way, they are accessible to attack adjustment tools during the course of production. However, in the case of the local relay, it is then necessary, during further assembly, to cover the saved base ends with additional cap-like base parts, so that the base thus supplemented can form a closed housing together with a cap. This housing can then be sealed in a known manner with potting compound or a curable adhesive.

It has been shown, however, that changes in relays of the above-mentioned type occur in particular even after the housing has been closed, which may be greater than the originally existing deviations which can be remedied by the aforementioned adjustment during manufacture. The causes of these changes are tensions and relaxation, which occur during tempering processes, in particular when casting and when the casting compound is hardening, and which are further amplified in polarized relays under the influence of the magnetic force of the permanent magnet on the armature. The corresponding relaxation processes must take place during the manufacturing process, so that no subsequent changes in characteristic values occur when the relay is used later.

The aim of the invention is to provide a relay of the type mentioned at the outset and a method for its production, in which, after all the structural parts have been assembled, after the housing has been closed and after all intermediate parts have been sealed. column construction and housing parts existing column

Adjustment is possible.

According to the invention, this is achieved in a relay of the type mentioned at the outset in that the base plate has a window-shaped recess which is open to the outside in the region below each contact carrier section. In this way, the contact carrier section can be bent through the cutout for adjustment even after the relay has been assembled, a predetermined bending point preferably being provided in the vicinity of the clamping of the contact carrier section.

Instead of the connection via a predetermined bending point, the contact carrier section can also be pivoted about torsion bars, approximately in the middle between two free ends. In this case, the fixed contact is optionally moved up or down by torsion of this suspension, depending on which end of the contact carrier section an adjustment pin is attached to.

The shape of the recess is expediently more or less precisely adapted to the circumferential contour of the respective contact carrier section, so that this contact carrier section largely covers the recess on the inside of the housing. In this way, the recess can be sealed with a drop of an adhesive after the adjustment, without this adhesive running into the interior of the housing.

The method according to the invention for producing such a relay consists in the fact that after the installation of the electromotive gnetsystems on the base provided with the contact element and after the known closing and sealing of the housing - with the exception of the recesses below the contact carrier sections - the respective contact carrier section for setting a predetermined contact distance from an associated movable contact element by means of a through the recess of the base-engaging adjustment tool is deformed in its angular position relative to the clamping point.

This adjustment is carried out primarily by means of an adjusting pin which presses and deforms the contact carrier section clamped on one side towards the interior of the housing. In this case, the tolerances in production are expediently chosen such that the contact carrier sections are slightly bent toward the outside. In principle, however, it cannot be ruled out that, with suitable tools, the contact carrier sections will subsequently be bent outwards. This can either be done by hook-shaped adjustment tools which, given a correspondingly large dimensioning of the cutout, engage the contact carrier section and pull it outwards, or adjustment tools attacking with suction forces on the outside of the contact carrier section could also be used. When the contact carrier section is suspended via torsion bars, adjustment in two directions is possible in any case.

It is essential with the invention that the setting process takes place at a point in time at which the relay is almost finished. This means that the relay is already completely assembled, possibly also magnetized, cast and tempered. pert is. All relaxation and tensioning processes have thus already been completed. The subsequent sealing of the cutouts, which is still necessary, can be carried out with the sealing of ventilation holes, which is necessary anyway; by filling an adhesive, for example a UV adhesive, into the cutouts, the adjusted contact carrier sections are also finally fixed.

The invention is explained in more detail using an exemplary embodiment with reference to the drawing. It shows

FIG. 1 shows a polarized miniature relay designed according to the invention in a longitudinal section,

FIG. 2 shows an end view of the relay from FIG. 1 with the cap cut open and parts partially cut,

FIG. 3 shows a view of the top of the base of the relay from FIG. 1,

4 shows a view of the underside of the base of the relay from FIG. 1, FIGS. 5 to 8 show a detailed view of a contact carrier section of the relay from FIG. 1 in various manufacturing or adjustment phases,

9 shows a detailed view of the armature and the contact arrangement from FIG. 2 with an additional test pin, FIGS. 10 to 12 show a detailed view of a contact carrier section with central suspension via torsion bars in various adjustment phases and

Figure 13 is a detailed view of a contact carrier section with an additionally attached contact spring. The polarized relay shown in the drawing has a structure known per se. A base 1 forms a base plate 2, which defines a base plane of the relay, and partially circumferential side walls 3. Fixed contact elements 4, which form stamped out of a common circuit board, are embedded in the base and form connecting lugs 5 emerging from the underside of the base plate. At their ends, these fixed contact elements 4 each form contact carrier sections 6, each of which carries a fixed contact 7.

Underneath each contact carrier section 6, a recess 8 is provided in the base plate, over which the respective contact carrier section 6 extends in a self-supporting manner. The circumferential contours of the recess 8 and the contact carrier section 6 are matched to one another without space or with little play so that the free end of the contact carrier section can be moved into the recess 8. In the vicinity of its clamping point, each contact element 6 also has a notch 9 which forms a predetermined bending point.

A cap 10 forms, together with the base 1, a closed housing in which a magnet system with a coil 11 on a coil body 12, a rod-shaped core 13 and two yokes 14 and 15 is arranged in the upper region. A rod-shaped, three-pole permanent magnet 16 is arranged between the free ends of the yokes, at the center pole N of which an elongated armature 18 is mounted via a bearing plate 17. Two center contact springs 20 are fastened to the armature 18 via a plastic carrier 19 and each carry 21 movable contacts 22 at two ends of the spring. Everyone who moves Chen contacts 22 is located above a fixed contact 7 and is optionally interconnected with the armature 18 in accordance with the rocking movement. The two contact springs each have laterally bent connecting tabs 23, which are only indicated in FIG. 1 and also serve as bearing strips for the armature in a manner not shown in any more detail. The structure and function of such a relay are generally known and do not need to be explained further here.

In the manufacture of the relay, the armature 18 is first arranged and fastened on the base 1, then the magnetic system is placed on and connected to the base. The cap 10 closes the housing and is sealed in a known manner; the coil can also be cast in the housing, for example.

Even if the contact distances between the fixed contacts 7 and the movable contacts 22 are set during the assembly of the armature with the contact springs 20, they can become undesirable again in the course of further production, in particular due to temperature changes when the relay is sealed to change. For this reason, the recesses 8 can be used to adjust the contact spacing even after the housing has been closed. For this purpose, each of the contact carrier sections 6 is pressed from below via adjusting pins 24 until the contact distance has reached the predetermined value.

The setting process can be seen with reference to Figures 5 to 8. According to FIG. 5, the contact carrier section 6 is arranged in the base plate 2 exactly parallel to the base plane. The edge of the Recess 8 is designed such that the contact carrier section 6 can be pivoted about the predetermined bending point formed by the notch 9 both downwards to the outside of the base according to FIG. 6 and upwards to the inside of the base according to FIG. Since it is easier to simply press the contact pins 24 from the outside with the adjusting pins 24 shown in FIG. 1 and to bend them to the inside as shown in FIG. 7, it may be advisable to according to the contact carrier sections 6 before the relay is assembled Figure 6 to bend slightly outwards so that the final adjustment after assembly must be made in a bend to the inside. However, it would also be conceivable to bend the contact carrier section according to FIG. After the adjustment, an adhesive 25 is filled into the recess 8, which fixes the adjusted contact carrier section and finally seals the housing. This adhesive is expediently self-curing, so that it is not necessary to reheat the entire housing. As can also be seen in FIG. 4, the adhesive can be filled into a trough 28, from which it then flows simultaneously into a ventilation hole 27 which is required anyway and into the recess 8.

In the relay shown in FIG. 1, the adjustment process can take place approximately in the following way: if the permanent magnet 16 of the polarized system is magnetized, the armature is not in the middle position shown, but is at one end on a yoke, for example on the yoke Yoke 14, on. In this case, the contact spring 21 with the movable contact 22 on the opposite side, So in Figure 1 on the right side against the fixed contact 7. If this is not the case, the contact carrier section 6 is pressed in via the adjusting pin 24 until contact is made with the movable contact 22. This can be measured via the contact connections. A path corresponding to the minimum overstroke is then additionally adjusted. This ensures the lower limit of the burn-up safety. The relay is then switched so that the opposite contact side can also be adjusted in the same way.

A response value can also be set in each case by bending the contact carrier sections 6. In this case, the relay is energized with a ramp-up or down value until it switches. If the excitation value measured at the time of response is not within a target range, the resetting force on the relevant side can be increased by readjusting the contact carrier sections, so that the relay switches over when the excitation is lower or correspondingly higher.

However, it is also possible to measure mechanical values on the closed relay and to readjust the contact carrier sections accordingly. This is possible, for example, by means of a measuring pin 26 which is inserted through the ventilation hole 27 below the armature and switches it mechanically. In this process, a force-displacement measurement can be carried out, which in turn can then form the basis for readjustment of the contact carrier sections.

Finally, it should also be pointed out that the principle according to the invention does not relate to the position shown by way of example. Lararized rocker arm relay is limited, but that such an arrangement of fixed contact elements and a corresponding adjustment on the closed housing can also be provided in other relay constructions and in other polarized or neutral magnet systems.

By readjusting, spreading between the two contact springs 21 can also be compensated individually. If, for example, the contact distances a1 and a2 in FIG. 9 differ due to a spreading of the contact springs, which can be determined by electrical measurement of the closing time, the same contact distance can be produced on both sides by differently bending the contact carrier sections 6.

FIGS. 10 to 12 show a further embodiment of a contact carrier section analogous to FIGS. 5 to 7. In this case, a contact carrier section 28 is cut free with both ends above the cutout 8 and connected in the middle on both sides to the fixed contact element 4 via torsion bars 29. In the drawing, a section through one of the torsion bars 29 is shown. Thus, in this embodiment, the adjusting pin 24 can optionally be used to press one end below the fixed contact 7 according to FIG. 11 or the other end according to FIG. Accordingly, the fixed contact is moved upwards or downwards, the torsion webs 29 being permanently deformed. The recess 8 can then be cast in the same way as in FIG. 8. FIG. 13 shows, in a further modification, a contact carrier section 30, to which the fixed contact 7 is not fastened directly but via a contact spring 31. Otherwise, this contact carrier section 30 can be adjusted in the same way as the contact carrier section 6 according to FIGS. 1 to 8.

Claims

claims

1. Electromagnetic relay

with a base (1) made of insulating material, which defines a base plane with a base plate (2) and which is part of a closed housing,

- With fixed contact elements (4) anchored in the base (1), each having a connecting lug (5) leading to the outside of the housing and one cantilevered in the housing interior, cantilevered parallel to the

Have contact carrier section (6) extending on the base plane,

- With at least one contact spring (20, 21) which interacts with a contact carrier section and is also connected to a connecting lug (23) leading to the outside of the housing, and

- With an above the base (1) arranged in the housing electromagnet system with coil (11, 12), core (13) and armature (18) for actuating the at least one movable contact spring (20), characterized in that the bottom plate (2) in each case in the area below each contact carrier section (6, -28; 30) has a window-shaped recess (8) which is open to the outside.

2. Relay according to claim 1, characterized in that the shape of the recess (8) of the outer contour of the Kontaktträgerabschnit¬ tes (6, -2830) is adapted.

3. Relay according to claim 1 or 2, so that the contact carrier section (6; 30) in the vicinity of its clamping point over the edge of the recess (8) has a predetermined bending point (9).

4. Relay according to claim 1 or 2, so that the contact carrier section (28) is connected to the fixed contact carrier via torsion bars (29) approximately in the central region of the recess (8).

5. Relay according to one of claims 1 to 4, so that the contact carrier section (30) is connected to a contact spring which bears the fixed contact (7) on its side.

6. Relay according to one of claims 1 to 5, so that the recess (8) covered by the contact carrier section (6, -28; 30) from the housing inside is filled with potting compound (25) from the outside of the housing.

7. Relay according to one of claims 1 to 6, so that an opening (27) for introducing a test pin (26) is provided below the armature (18).

8. A method for producing a relay according to claim 1, wherein on the contact carriers (4) provided base (1) the electromagnet system (11, 12, 13, 18) is fastened and the housing (1, 10) is closed, characterized in that the respective contact carrier section (6; 28; 30) for setting a predetermined contact distance with respect to an associated be movable contact element (21) is deformed in its angular position with respect to the clamping point by means of an adjusting tool (24) which extends through the recess (8) of the base plate (2).

9. The method according to claim 6, so that the recess (8) after the adjustment by deformation of the contact carrier section (6) is filled with liquid, then hardening casting compound (25).

10. The method according to claim 6 or 7, so that the measure of a necessary readjustment of the contact carrier sections (6) is obtained by energizing the relay and by comparing a measured response or drop excitation with a target excitation.

11. The method according to claim 6 or 7, d a d u r c h g e k e n e z e i c h n e t that the measure for a required readjustment by mechanical actuation of the armature (18) via a test pin (26) and by a force-displacement measurement carried out thereby is obtained.