EP2042749B1 - Clip for planar cores - Google Patents

Description

The invention relates to a clip with which magnetic planar cores can be attached to printed circuit boards.

In the case of planar cores, there is the problem of mounting them in a predetermined position on a printed circuit board in such a way that, together with a coil prefabricated or printed on the printed circuit board, a magnetic component with narrow tolerances is obtained. For this purpose, it is particularly necessary to secure the planar cores positionally accurate and reliable, that is firm and stable against unwanted slipping. This is achieved according to the prior art, for example, by adhering the planar cores to the printed circuit board.

It is also known to attach the cores via a clamp on the circuit board, which hooks inserted through the circuit board to the core or snaps into the core. The problem with this known clip, however, is that the latching is not stable and the reliability of attachment by means of the clip is therefore limited.

Object of the present invention is to provide a reliable installation of planar cores on PCP circuit boards using an improved bracket.

This object is achieved by a clamp with the feature of claim 1. Advantageous embodiments of the invention can be found in further claims. Undercuts and noses. The two brackets are identical.

From the EP 1 315 184 A1 is a two-piece clamp for two-part E cores are known, the brackets have either latching or snap-in pockets. To clamp the arms of a bracket must be compressed against a spring tension.

From the DE 40 29 704 A1 is known a two-iron clamp, which has a hook on each arm, which can hook with the hook of the other bracket.

Out DE 88 09 122 U1 is a one-piece clamp known, which can snap into place by means of latching means on an edge of a bobbin.

This object is achieved by a clamp with the feature of claim 1. Advantageous embodiments of the invention can be found in further claims.

It is specified a bracket consisting of a) a bracket with a yoke and two bracket arms and b) consists of a bow-shaped spring clip with a bridge and two spring arms. The bracket and spring clip are each formed as separate but mutually engageable, bent stampings. For this purpose, the arms each have fixing elements on the ends, which allow a corresponding engagement. Thus, a first stamped part at the ends of its two arms each have a nose with a latching, while the second stamped part at the ends of the arms in each case has a matching Einrastbügel with an undercut, in which the Einrastbügel can engage.

The assignment of the fixing elements to the two stamped parts includes both possibilities. Thus, the first stamped part may be the spring clip and the second stamped part of the stirrups or vice versa. In all cases, the spring arms can be pushed onto the hanger arms, wherein the spring arms spread apart until the latching arms slide over the lugs and engage in the undercut by the spring tension of the spread spring arms, wherein the ends of the spring arms jump back a little bit. The nose with the latch then prevents that interlocked bracket and spring clamp can be separated from each other by train again and are therefore securely fixed. A release of the connection is possible only after spreading the spring arms. But this counteracts the spring tension. A spring tension is ensured when the spanned by the ends of the spring arms opening width is less in the loose untensioned state than in the fixed state.

With the clamp two- or multi-part body can be fixed to each other in a simple manner. Advantageously, the clip is then designed so that it follows the outer circumference of the two bodies in the connected state. Then the clip can rest against the bodies over a maximum length following the outer circumference. Advantageously, this outer circumference is substantially rectangular, so that the bracket and spring clip together are rectangular or individually U-shaped.

However, it is also possible to fix bodies with differently shaped outer circumference by a correspondingly shaped clamp against each other. It is also possible that the clip follows the shape of the respective outer circumference only in sections. For example, the edges of the outer circumference of the body may also be rounded, while the stamped parts are bent angularly, or vice versa.

Moreover, it is possible to use at least one clip half, that is to say a stamped part for fixing bodies, which have a different overall size and in particular a different overall height. In this case, a bracket with different sized spring clips can be combined to different height brackets.

It is also possible to provide different latching positions in a clamp, for example two or more latching clamps which are arranged at different longitudinal positions of the corresponding arm. It is also possible to provide several arranged at different longitudinal positions of the corresponding arm lugs and notches. The respective latching possibility closer to the yoke or the bridge can then be adjusted by simply pushing the bracket and spring clamp together. In this way, the same bracket can be used for at least two different attachment problems, the differently sized total scopes of the two bodies.

A preferred application finds the clip as mentioned in the attachment of planar cores to printed circuit boards having printed coils. It even succeeds to fix three parts by the clip each other.

The self-spreading guide the arms of the clip allows easy mutual attachment and thus easy connection of the two bodies by means of the clip.

The clip is advantageously formed as a stamped part, in particular of a metal sheet. Advantageously, at least the spring clip made of spring steel is formed. Advantageously, both stamped parts are formed from the same material. In particular, the clip may be formed of stainless stainless steel or provided with a corrosion inhibiting coating.

The undercut on the arm of a stamped part may be formed as arranged behind the latching indentation, recess or taper.

In a recess, the corresponding arm tapers in a limited section. A taper extends over the entire arm, so that the ends of the arms are T-shaped, while a recess centrally at the end of the arm as a framed on all sides opening of the arm is trained. Thereafter, the arm with unchanged width can continue towards the web, or taper. All undercuts have in common that there the corresponding arm has a pointing towards the rear web or yoke edge. After the latch has slid over the nose and locked, this is done fixing the two stampings on these edges.

In a preferred embodiment, the lugs are attached to the bail arms and each have two outwardly facing guide edges over which the latch is guided when pushing, with the spring arms of the spring clip spread apart. The leading edges then extend from the end of the hanger arms to the yoke out towards the outside. An inwardly extending or kinking portion of the leading edge forms the latching.

In an alternative embodiment of the clip, the tabs are attached to the spring arms and each have two inwardly facing guide edges which spread apart the spring arms when pushing the spring clip on the latch. The leading edges then have a to the web towards the formation of latching outwardly extending portion. The bevel of the spring arms even over the correspondingly extending leading edges thus ensures their spreading.

In both cases, the in the preferred example inwardly extending portion in extension of the leading edge - or in the alternative example outwardly extending portion - have a locking nipple, which fixes the latching clip after locking in this position. A latched clip that stands by pulling apart of the stamped parts each in the direction of web or yoke under tensile load, can not be solved by simply spreading the spring arms from the latch, since the locking nipple prevents spreading. In this embodiment, the two stampings are particularly well fixed together and protected against accidental release of the clip connection.

In one embodiment, the spring arm is curved in the region of the latching strap outwards so that the respective latching clip when sliding the arms against each other so not with edge but with the rounded (inner) surface is guided over the leading edges of the nose. This prevents jamming and facilitates the postponement.

The spring clamp is intended to set a spring action against the spreading apart of the spring arms. In a suitable shape, the spring clamp on a central region and two L-shaped curved in the spring arms expiring areas. The L-shaped bent portions are bent back towards the middle area. In this kink, part of the deformation takes place during spreading. Advantageously, the spring arms extend towards their ends to the outside, so that the opening width of the spring clip at the ends of the spring arms is greatest. The spreading of the spring arms and in particular this kink between the central region and L-shaped bent part also lead to the spring clip is after locking in the bracket under a spring tension that presses the web of the spring clip against the body to be fastened with the clip. At the same time by the spring tension on the other side and the yoke of the bracket against this or the second body to be fastened pressed. This ensures that both connected to the clamp body are pressed firmly against each other and are thus fixed in this axis against each other.

Unlike the bracket, the arms of which are preferably verkickt or bent inwards against the yoke. In this embodiment, the bracket is also after being pushed onto a body by the required spreading apart of the hanger arms already under a certain bias, which cause a tight and firm concern of the hanger arms on the body and thus already allow a certain fixation.

With the clip according to the invention fixation of at least two bodies against each other or against a third body can be made. An advantageous arrangement is the clamp described above, a two-part magnetic planar core and a printed circuit board having a printed coil. The two halves of the two-piece planar core sit on either side of the circuit board above the printed coil on the circuit board. In this case, the circuit board on two openings, which are arranged on two opposite edges of the planar core. Through this, the clip can be guided so that it encompasses the two planar core halves. For this purpose, the bracket is attached from one side of the circuit board forth on the Planarkern that his bow arms point in the direction of the openings or are inserted into this. The spring clip is then attached from the other side of the circuit board forth on the Planarkern and the hanger arms that spring clip and bracket are engaged with each other. Thus, the clamp fixes the two halves of the planar core through the apertures and crosses the printed circuit board.

The plugging does not require any special tools and can therefore be carried out in a simple yet nevertheless successful manner, even with a printed circuit board which has a high assembly density, leaving little or no space for applying a tool for fastening the clip.

In one embodiment, at least the yoke, the central region of the web and the Einrastbereich of the arms at the Planarkern are firmly. The yoke and bridge can be widened in relation to the arms and thus present a larger contact surface with the bodies to be fixed.

In a further embodiment, the circuit board has further openings in the region of the lower edges of the planar core, are inserted through the correspondingly formed parts of a Planarkernhälfte and thus are in direct contact with the second Planarkernhälfte. As a result, the magnetic circuit of the planar core is closed.

A preferred use of the clip is the attachment of magnetic planar cores of types E, ER and EQ to printed coil printed circuit boards.

With the clip can be dispensed with the gluing of the planar cores on the circuit board with the planar coil, since the bracket itself already allows a sufficiently strong and secure against loosening of the connection attachment of the planar cores. Thus, on the one hand eliminates the thermal stress that is otherwise required for curing the adhesive bond. Slipping while gluing is no longer possible. The core halves of the Planarkerne may for this purpose have corresponding guide grooves in which the clamp halves are held or guided.

In the following the invention will be explained in more detail by means of exemplary embodiments and the associated figures. These serve only to illustrate the invention and are therefore only roughly schematic and not true to scale, so that the figures neither absolute or relative dimensions can be taken.

• Figur 1 einen schematischen Querschnitt durch eine zweiteilige Klammer,
• Figur 2 mögliche Ausführungen der Enden der Federarme mit dem Einrastbügel,
• Figur 3 verschiedene Ausführungen der Enden der Bügelarme mit der Nase und den Führungskanten im schematischen Querschnitt beziehungsweise in perspektivischer Darstellung,
• Figur 4 eine bevorzugte Ausführung einer Federklemme im schematischen Querschnitt und in der Draufsicht,
• Figur 5 eine bevorzugte Ausführung eines Bügels im Querschnitt und zwei Draufsichten,
• Figur 6 ein induktives Bauelement mit Planarspule und Planarkernhälften, die mit Hilfe der Klammer befestigt sind, im schematischen Querschnitt und in der Draufsicht,
• Figur 7 einen schematischen Querschnitt durch eine alternative Ausführung einer Klammer, bei der die Arme mit Einrastbügel und Nase gegenüber Figur 1 vertauscht sind.

Show it:

• FIG. 1 a schematic cross section through a two-part bracket,
• FIG. 2 possible embodiments of the ends of the spring arms with the latch,
• FIG. 3 various embodiments of the ends of the hanger arms with the nose and the guide edges in schematic cross-section or in perspective view,
• FIG. 4 a preferred embodiment of a spring clip in schematic cross-section and in plan view,
• FIG. 5 a preferred embodiment of a bracket in cross-section and two plan views,
• FIG. 6 an inductive component with planar coil and planar core halves, which are fastened by means of the clamp, in schematic cross-section and in plan view,
• FIG. 7 a schematic cross-section through an alternative embodiment of a clip, in which the arms with latch and nose opposite FIG. 1 are reversed.

FIG. 1 shows a bracket BG and a spring clip FK in schematic cross-section. The bracket consists of a metal strip, which forms a yoke J and is bent on both sides, whereby bracket arms BA are formed. At the end of the hanger arms in each case a nose N is arranged.

The spring clip FK shown below forms the second part of the clip and consists of a metal strip which has a web ST and which is bent on both sides to form spring arms FA. At the ends of the spring arms in each case a latch EB is arranged, which has an undercut HS.

Bracket BG and spring clip FK are made in particular as bent punched parts of a sheet steel strip and preferably spring steel. The nose N of the bracket BG has at least one leading edge FU, which allows a simple sliding of the spring clip FK. When the spring clip FK is pushed on, the latching clip is guided over the leading edge FU by movement in the X direction, the spring arms FA of the spring clip FK being forced apart in the spreading direction SR due to the bevel of the leading edge FU. Once the latch EB is slipped over the nose, the spreading of the spring arms is reversed by acting as restoring force spring action and the nose can engage in the undercut HS of the spring clip FK.

In FIG. 2 are several ways shown in plan view, as the end of the spring arms can be performed with the latch EB and the undercut HS. A simple possibility is to form the end of the spring arms FA T-shaped, wherein the latch EB forms the transverse part of the T. Corresponding designs are in Figure 2A and Figure 2C shown. Furthermore, it is possible to realize the undercut HS of the end of the spring arm as a recess, wherein the recess in the figure above limiting strip represents the snap-EB, as shown in FIG. 2B is shown. FIG. 2D shows as a further possibility a loop-shaped design of the end of the spring arm, wherein the upper part of the loop in turn represents the latch EB. In contrast to FIG. 2B Here, the spring arm tapers after the recess, also in Figure 1A in comparison to Figure 1B.

The T-shaped snap-in according to the embodiments 2A and 2C cooperate advantageously with a bracket BG, which has two parallel arranged lugs, which can engage on both sides of the T middle beam in the two undercut HS. The embodiments according to the Figures 2B and 2D can interact with a single, preferably broad nose. It is possible, however, to combine these versions with a bail arm BA, which has two noses.

Possible designs of noses and leading edges are in FIGS. 3A to 3C shown in schematic cross section. In FIG. 3A the nose is formed by the fact that the end of the metal strip forming the bail arm BA outwards and backwards (X-direction in FIG. 1 ) is bent so that the bent part simultaneously represents the leading edge FU.

FIG. 3C shows a variant of this embodiment, in which the end of the bail arm BA is first bent outward and then back down and obliquely inwards, wherein the obliquely downward end forms the leading edge FU.

In contrast, in the embodiment according to FIG. 3B the lugs formed with the leading edge FU by laterally bending a correspondingly shaped end of the bail arm BA. Accordingly, the nose is not formed by bending but results from the corresponding punched or cut end, so to speak is "solid" formed.

Figure 3D shows a schematic representation of a possible modification of embodiments according to the FIGS. 3A and 3C , There, the nose is not formed from the entire end of the bail arm. Rather, here a rectangular strip is cut out on three sides and bent out, which forms a protruding tab, which can be bent as shown to a nose N.

FIG. 4A shows a preferred embodiment of the spring clip in schematic cross-section. The web of the spring clip has a central region MB, in which the web runs "horizontally". On both sides of the central region, the spring clip FK is slightly bent in the figure upwards and then sharply down, forming an L, the end of which represents a spring arm. At the end of the spring arm of the metal strip which forms the spring clip, preferably bent around outwards. This round turn allows for a particularly easy and easy sliding of the latching over the leading edges FU am in FIG. 4 Bail arm BA not shown.

FIG. 4B shows a preferred embodiment of the Einrastbügels EB in the outside of the page. The Einrastbügels is formed as a cross piece of the T-shaped end of the spring arm FA. The curvature can be made solely in the region of the latch EB, as indicated by the dotted lines in FIG. 4B is shown.

FIG. 5A shows an advantageously suitable bracket BG, which like the corresponding embodiment in FIG. 3B can be obtained by laterally bending the ends of the hanger arms along the longitudinal edge of the bracket BG. The nose N preferably also has a locking nipple RN, behind which the latch EB can engage.

FIG. 5B shows the end of the bail arm BA from the outside. In this illustration, it can be clearly seen that the nose can be obtained by laterally bending a metal strip extended in the end. FIG. 5C shows the bracket from above, here too the outwardly bent ends which form the nose N, are clearly visible.

FIG. 6 shows in schematic cross section a Planarkern, which is fixed by means of the clip according to the invention on a printed circuit board LP, on which a printed coil SP is provided. The planar core PK is formed in two parts, wherein both parts may be formed in cross-section E-shaped.

On the circuit board LP two perforations DB are provided on both sides of the planar core PK, which is to plug through at least part of the clip are suitable. Preferably, the circuit board on further openings, through which the legs of the E-shaped planar core can be performed. By direct impact contact with the lower part of the planar core PK so the magnetic circuit can be closed by both Planarkernhälften.

For fastening by means of the clip according to the invention, the bracket BG is first pushed onto the upper half of the planar core PK. Depending on the configuration, the yoke arms BA can be so long that they are already guided through the aperture DB and protrude on the underside again. In the next step, the spring clip FK is now pushed onto the bracket BG from the underside so that the latching clip slips over the leading edge, spreads the spring arms outwards and finally snaps firmly behind the nose with the undercut of the latching clip.

FIG. 6B shows the arrangement in plan view. The bracket BG is shown here as a strip, but may be widened in the yoke or even have lateral yoke arms to keep the Planarkern even better. Also shown is the coil SP and the inside located in cross-section E-shaped core. The opening DB can be adapted exactly to the size of the bracket BG or the spring clip FK, so that the edges of the clip flush with the side edges of the opening and thus prevent slipping of the clip in the attached state. The planar core PK can also have a groove within which the clamp can extend, so that slipping of the planar core in the clamp is not possible.

FIG. 6A shows that the bracket BG advantageously rests on all sides on Planarkern PK, while the spring clip FK rests at least in the central region at the bottom of the lower part of the planar core PK '. Preferably, the spring arms are designed so that they can form a pressure contact to this on both sides of the planar core at least at one point.

FIG. 7 shows a further embodiment in which, in contrast to the previously described embodiments and in particular in contrast to FIG. 1 the lugs are arranged at the ends of the spring arms of the spring clip FK. Thus, here the ends of the arms of bracket and spring clip are reversed, but with the leading edges of the tabs N on the spring clip FK are designed so that they point inwardly to Federklemmeninneren. If the spring clip FK is pushed onto the bracket BG in the X direction, the leading edge FU also leads to a spreading of the spring arms of the spring clip in this embodiment.

The invention is not limited to the embodiments shown in the embodiments and can be varied within the scope of the claims. In particular, any sub-combinations of the individual features are possible. Also, the clip is not limited to a particular material or shape.

LIST OF REFERENCE NUMBERS

BG

hanger

J

yoke

BA

Ironing arms

N

nose

FK

spring clip

ST

web

FA

spring arms

EB

engaging clips

HS

undercut

FU

leading edge

RN

Rest nipple

MB

Middle area of the spring clip

PK

Planar

LP

circuit board

SP

printed coil

DB

perforations

X

push-on

SR

the spreading

Claims (15)

1. Clamp

   - comprising

   a) a bracket (BG), having a brace (J) and two bracket arms (BA), and

   b) a bracket-like spring terminal (FK), having a crosspiece (ST) and two spring arms (FA),

   - wherein the bracket and spring terminal are each designed as bent punched parts which are separate, but can be latched one inside the other,

   - wherein a first punched part, at the ends of the arms (BA), has a respective nose (N) with a latching-in means,

   - wherein a second punched part, at the ends of the arms (FA), has a respective latching-in bracket (EB) with an undercut (HS),

   - wherein the noses (N) of one of the punched parts have guide edges (FU), which spread the spring arms (FA) of the spring terminal (FK) apart from one another when the latching-in bracket (EB) is pushed on,

   - wherein the latching-in bracket is designed such that it can be latched in at the undercut.
2. Clamp according to Claim 1,
   in which the first punched part is the spring terminal (FK) and the second punched part is the bracket (BG).
3. Clamp according to Claim 1,
   in which the first punched part is the bracket (BG) and the second punched part is the spring terminal (FK).
4. Clamp according to one of Claims 1-3,
   in which at least the spring terminal (FK) is formed from spring steel.
5. Clamp according to one of Claims 1-4,
   in which the undercut (HS) is designed as a depression, recess or tapered portion which belongs to the respective arm and is arranged behind the latching-in bracket (EB).
6. Clamp according to one of Claims 3-5,
   in which the noses (N) are arranged on the arms (BA) of the bracket and each have two outwardly oriented guide edges (FU), wherein the guide edges have an inwardly running portion for forming the latching-in means.
7. Clamp according to one of Claims 2, 4 and 5,
   in which the noses (N) are arranged on the arms (FA) of the spring terminal and each have two inwardly oriented guide edges, wherein the guide edges have an outwardly running portion for forming the latching-in means.
8. Clamp according to Claim 6,
   in which the inwardly running portion has a latching nipple (RN), which fixes the latching-in bracket (EB) in position once it has been latched in.
9. Clamp according to either of Claims 6 and 8,
   in which the spring arm (FA) is curved outwards in the region of the latching-in bracket.
10. Clamp according to one of Claims 1-9,
    in which the spring terminal (FK) has a central region and two regions which are bent in an L-shaped manner and run out into the spring arms,
    in which the regions which are bent in an L-shaped manner are angled in the rearward direction towards the central region,
    in which the spring arms run outwards in the direction of their ends, and therefore the opening extent of the spring terminal is greatest at the ends of the spring arms.
11. Clamp according to one of Claims 1-10,
    in which the bracket arms (BA) are angled or bent inwards towards the bracket brace.
12. Arrangement with the clamp according to one of the preceding claims, having a two-part magnetic planar core (PK) and a printed circuit board (LP) comprising a printed coil,
    in which the two halves of the two-part planar core are seated over the printed coil, on either side of the printed circuit board,
    in which the printed circuit board has two through-passages, which are arranged on two opposite edges of the planar core,
    in which the bracket (BG) is plugged onto the planar core from one side of the printed circuit board such that its bracket arms (BA) are oriented in the direction of the through-passages or are plugged into the same, in which the spring terminal (FK) is plugged onto the planar core from the other side of the printed circuit board such that the spring terminal and brackets are latched one inside the other and the clamp fixes the two halves of the planar core on the printed circuit board with engagement through the through-passages.
13. Arrangement according to Claim 12,
    in which at least the bracket brace (J), the central region of the crosspiece (ST) and the latching-in region of the arms butt firmly against the planar core (PK).
14. Arrangement according to Claim 12 or 13,
    in which the printed circuit board (LP) has further through-passages in the region of the lower edges of the planar core (PK), through which appropriate formed parts of a planar-core half are plugged, and therefore the magnetic circuit is closed as a result of direct contact with the second planar-core half.
15. Use of the clamp according to one of Claims 1-11 for fastening magnetic planar E, ER and EQ cores (PK) on printed circuit boards with printed coils.

Images