JP4631564B2 - Floating nut and printed circuit board - Google Patents

Description

The present invention relates to a floating nut and a printed circuit board to which the floating nut is attached .

  First, as a background art, there has been a method characterized in that a nut is mounted on a printed circuit board by soldering alone and an electronic component is fixed to the printed circuit board (see Patent Document 1).

According to this method, the position of the nut is determined only when it is fixed on the printed circuit board. Therefore, when the screw is used for fixing to the electronic component, the screw's central axis is the tolerance of the hole diameter of the printed circuit board. Center axis misalignment occurs due to cumulative tolerances such as installation error, nut outer dimension tolerance, nut installation error, and dimensional tolerance of electronic component hole positions. As a result, there has been a problem that the electronic component cannot be attached due to the misalignment of the central axis between the screw hole of the electronic component and the nut on the printed circuit board, or the electronic component is stressed due to the forced attachment and the reliability is lowered.

On the other hand, in order to absorb the cumulative tolerance as described above, a method using a floating nut has been proposed. Conventional floating nuts mainly have a feature constituted by a method of caulking to a sheet metal part (see Patent Document 2).

However, in caulking, since a large stress is applied to the components to be caulked, an uneasy factor such as damage to the wiring pattern on the substrate and the electronic components occurs on the board on which the electronic components are mounted. There was a problem of lacking.
In addition, since the outer shape of the component becomes large due to the caulking structure, there has been a problem that greatly hinders the arrangement area when the electronic component is arranged on the substrate.

Further, as a method for fixing two substrates using an inter-board connector, a method is generally used in which each substrate and a housing are fixed with a tapping screw and the connectors are fitted together. However, when this inter-board connector is a surface mount type, the fitting allowable value between the connectors was a very severe value.
As a method of absorbing the accumulated tolerance in order to fit within this severe allowable value, conventionally, for example, the use of a floating connector and the clearance amount of the fitting spigot between the housings are supported. (See Patent Document 3).

However, the floating connector has a large outer shape due to its structure, and the mounting area is limited. In addition, there are few types of floating connectors, and the selection range is narrow.
Further, in the method of absorbing the accumulated tolerance by the clearance of the housing inlay, the clearance amount leads to the fitting displacement between the housings, so that the design and appearance as a product are deteriorated when the housings are fitted together. There is a problem.

JP-A-9-137815 JP 2003-181587 A JP 2003-295909 A

The present invention has been made to solve the above-described problems in the prior art, and an object thereof is to obtain a floating nut capable of absorbing cumulative tolerance and a printed circuit board to which the floating nut is attached .

The floating nut according to the present invention is formed by penetrating and covered with a mounting member having at least two lead pins for inserting and soldering into a predetermined hole formed in the printed circuit board so as to be wrapped by the mounting member. The printed circuit board includes a nut having a movable region.

  In the printed circuit board according to the present invention, the floating nut is attached by an attachment member.

  According to the floating nut and the printed board according to the present invention, there is an effect that the accumulated tolerance can be absorbed.

Embodiment FIG. 1 is a plan view (a), AA sectional view (b), front view (c), BB sectional view (d), and side view (e) of a floating nut in the present embodiment. ). As shown in this figure, the nut 1 is covered with a mounting bracket 2 that is formed so as to penetrate the nut 1. Therefore, the nut 1 floats in the movable region covered with the mounting bracket 2 and can be freely changed in position. The clearance amounts α1 and α2 shown in the AA cross section (b) and the BB cross section (d) are distances at which the nut 1 can float, and the nut is movable in this movable region. This clearance amount has an effect of absorbing the accumulated tolerance due to the combination of parts in the prior art by floating the nut at the position where the screw enters.

FIG. 2 is a view for explaining the anti-rotation effect of the floating nut in the present embodiment shown in FIG.
As shown in FIG. 2, when the nut 1 tries to rotate in the movable region covered with the mounting bracket 2, the relationship between the outer diameter dimension a of the nut 1 and the outer diameter dimension b of the mounting bracket 2 is a> b. Therefore, there is an effect of preventing the nut 1 from rotating. Thus, the screw can be fastened and fixed without holding the nut with a tool.

FIG. 3 is a view showing a state in which the floating nut 4 shown in FIGS. 1 and 2 in the present embodiment is attached to the printed circuit board 3.
As shown in this figure, the lead pins c1, c2 of the floating nut 4 are inserted into the holes d1, d2 of the printed circuit board 3, and the lead pins c1, c2 are surfaces e1, opposite to the surface on which the floating nut body is mounted, It is fixed to the printed circuit board 3 by soldering at e2. As a result, it is not necessary to use a special tool used for caulking or the like, and since the structure is simple compared to the caulking structure, the outer shape of the floating nut 4 can be made compact. There is an effect that the mounting area of the other components (for example, connector f1) can be widely used.

FIG. 4 is a diagram showing a configuration of the structure according to the present embodiment, and is a diagram showing a state in which the structure is disassembled. This figure shows a configuration example using the printed board 3 on which the floating nut 4 and the connector f1 shown in FIG. 3 are mounted.
Below, in order to demonstrate the structure of the said structure, the manufacturing process of the said structure is demonstrated in order. First, in a state where the printed circuit board 5 on which the connector f2 is mounted is fixed to the housing 6, the printed circuit board 3 with the connector f1 shown in FIG. 3 is connected by fitting the connectors f1 and f2 together. Next, the casing 8 is fitted into the casing 6 by using the inlays (that is, the concave and convex portions of each other) g1 and g2. Then, the screws 9 and 10 are inserted into the floating nut holes i1 and i2 of the printed circuit board 3 with connectors through the screw holes h1 and h2 of the housing 8 and screwed to the floating nuts 4a and 4b, thereby the printed circuit board 3 Is fastened and fixed to the housing 8.

In the structure according to the present embodiment, even when the connectors f1 and f2 are directly fitted together, the printed circuit board 3 is floated on the housing 8 without stress on the connectors f1 and f2 and the printed circuit boards 3 and 5. It can be fixed via nuts 4a and 4b.
Further, when the connectors f1 and f2 are fitted together, even if the floating nut holes i1 and i2 which are screw positions of the printed circuit board 3 and the screw hole positions h1 and h2 of the housing 8 are misaligned, the nut 1 Can be fixed at the same position without applying stress to the connectors f1 and f2. Therefore, there is an effect that contact reliability can be obtained by fitting the connectors f1 and f2.

In the present embodiment, a mounting bracket having a spring property may be used, and the floating nut 4 may be attached to the printed circuit board 3 by using the elastic force. By doing so, the mounting workability is improved. To do.
Alternatively, the mounting bracket 2 and the printed board 3 may be provided with screw holes, and the floating nut 4 may be attached to the printed board 3 through the screws. By doing in this way, the floating nut 4 (4a, 4b) can be more firmly fixed to the printed circuit board 3 compared with the fixing method using solder or a lead pin.

As described above, the floating nut according to the present invention is suitable for a component for fixing a printed circuit board. The printed circuit board according to the present invention is suitable for connection using a connector.

It is a figure which shows the structure of the floating nut concerning this Embodiment. It is a figure for demonstrating the detent effect of the floating nut concerning this Embodiment. It is a figure which shows the state which attaches the floating nut concerning this Embodiment to a printed circuit board. It is a figure which shows the structure of the structure concerning this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nut 2 Mounting bracket 3 Printed circuit board 4, 4a, 4b Floating nut 5 Substrate 6, 8 Case 9, 10 Screw a Maximum diameter of nut b Minimum diameter of movable area c1, c2 Lead pin d1, d2 Hole e1, e2 Floating nut Surface f1, f2 connector g1, g2 Inlay h1, h2 Screw hole i1, i2 Floating nut hole α1, α2 Clearance amount

Claims (3)

A mounting member having at least two or more lead pins for penetration and soldering into a predetermined hole formed in the printed circuit board ;
A nut whose movable region is secured by being covered so as to be wrapped by this mounting member;
Floating nut for printed circuit boards with The floating nut according to claim 1, wherein a minimum diameter of the movable region is smaller than a maximum diameter of the nut. A printed circuit board, wherein the floating nut according to claim 1 is attached by the attachment member.

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