JPH0220758Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field of the Invention The present invention relates to an improvement in the grounding structure of a shielded flat cable that is fitted and connected to a connector used in electronic equipment.

Background of the Technology Electronic devices such as digital computers that operate on low-level signals are susceptible to electrical noise.
Shielded flat cables are used to connect printed circuit boards that make up electronic circuits or between electronic devices because they tend to malfunction when noise is generated due to electrostatic discharge between the equipment and the operator. must be connected with a low impedance path.

Prior Art and Problems Figures 3 and 4 are diagrams showing conventional examples. Figure 3 is a plan view illustrating the grounding structure of a shielded flat cable that is grounded by drawing out the drain wire; FIG. 4 is a plan view illustrating the grounding structure of a shielded flat cable that is grounded by a connector.

In FIG. 3, 19 is a connector, 20 is a contact, 21 is a large number of parallel conducting wires that are press-contacted to the contact 20, 22 is an insulating coating surrounding the conducting wire 21, and 23 is provided outside the insulating coating 22. 24 is a protective coating, 25 is a drain wire drawn out from the shield layer 23, and 26 is a crimp terminal provided at the tip of the drain wire 25.

Further, in FIG. 4, reference numeral 27 indicates a drain line which is led in contact with the shield layer 23 and is pressed into contact with the contact 20.

In this way, the grounding structure of the conventional shielded flat cable consists of two shield layers, as shown in Figure 3.
As shown in FIG. In some cases, the drain line 27 led from the shield layer 23 is pressed into contact with the contact 20 of the connector 19 and connected to a grounding pattern of a printed circuit board (not shown).

However, such conventional drain lines 25, 2
In the grounding structure according to No. 7, the grounding impedance is high due to the diameter or length of the drain wires 25 and 27, and the grounding work is complicated and time-consuming.

Purpose of the Invention In view of the above-mentioned drawbacks of the conventional cables, it is an object of the present invention to provide a grounding structure for a shielded flat cable that allows easy grounding work and allows connection through a low impedance path.

Structure of the device In this device, a conductive grounding plate is provided that can ground the cable at the same time as the cable clamp, and the cable is wrapped around an insulating coating that wraps around multiple groups of conductors and has a shield layer on the outside. In the grounding structure of a shielded flat cable that is clamped by a cable, it is equipped with a conductive grounding plate that clamps the shield layer and clamps the cable.
The conductive ground plate has a contact portion that presses against the exposed portion of the shield layer, a locking piece that presses the contact portion against the shield layer and is attached to the connector, and a terminal portion that is connected to the ground point. This is achieved by providing a grounding structure for a shielded flat cable, which is characterized by:

Examples of ideas Embodiments of the present invention will be described below based on the drawings.

1 and 2 are diagrams showing one embodiment of the present invention. FIG. 1 is a perspective view showing the grounding structure of a shielded flat cable in an exploded state, and FIG. 2 is an assembled view of the grounding structure of the shielded flat cable. Each shows a perspective view showing the state, and the same reference numerals as those shown in FIGS. 3 and 4 indicate the same structure or the same part.

In FIGS. 1 and 2, 1 is an insulating housing, 2 is a lower protrusion protruding from both sides of the insulating housing 1, 3 is an insulating block, and 4 is hooked to the lower protrusion 2 and is connected to the insulating housing 1 and the insulating block. a locking portion of the insulating block 3 that prevents mutual separation from the insulating block 3;
5 is an upper protrusion protruding from both sides of the insulating block 3; 6 is an insulating cap; 7 is a locking element for the insulating cap 6 which is hooked onto the upper protrusion 5 to prevent the insulating block 3 and the insulating cap 6 from coming apart from each other; 8 is a holding part for holding the shield layer 23 between the insulating block 3 and the insulating cap 6; 9 is a contact part having a gutter-like cross section and pressing against the exposed shield part 10 of the shield layer 23; 11 is a contact part. 9 is a locking piece that is hooked onto the upper protrusion 5 to press it against the shield layer and prevents it from separating from the insulating block 3; 12 is a printed circuit board 14;
A terminal portion 1 that is inserted into a mounting hole 16 provided in a grounding pattern 15 and electrically connected by soldering.
Reference numeral 3 designates a conductive ground plate having an elastic force, such as a phosphor bronze plate for a spring, which is formed of the contact portion 9, the locking piece 11, and the terminal portion 12.

1 and 2, the shielded flat cable is electrically connected by pressing its conductor 21 into contact 20, and between the insulating housing 1 and the insulating block 3, the lower protrusion 2 and the locking part 4 are connected. It is fixed by fitting with. Thereafter, the holding portion 8 is bent to sandwich the shield layer 23, and the locking piece 11 and the upper protrusion 5 are fitted so as to press the exposed shield portion 10 with the gutter shape of the contact portion 9, thereby forming a conductive connection. The base plate 13 is fixed to the insulating block 3. Further, the insulating cap 6 is fixed to the insulating block 3 by fitting the locking portion 7 and the upper projection 5.

Incidentally, the insulating cap 6 does not need to be particularly provided if insulation from other electronic components is not required.

In this way, the shielded flat cable that is electrically connected to the connector is assembled by inserting the terminal portion 12 into the mounting hole 16 of the printed circuit board 14 and the contact 20 into the mounting hole 18, and then soldering it with a dip. The ground pattern 15 and the wiring pattern 17 are electrically connected to each other.

The grounding structure of the shielded flat cable constructed as described above is capable of grounding the shield layer 23 by surface contact of the contact portion 9 in the direction perpendicular to the longitudinal direction of the flat cable, and furthermore, the shield layer 23 can be grounded by surface contact of the contact portion 9 in the direction perpendicular to the longitudinal direction of the flat cable. The grounding to 14 is also ensured.

Further, since the connection to the connector and the connection to the printed circuit board 14 can be performed at the same time as the signal line connection work, no special grounding work is required.

In this embodiment, a structure in which the printed circuit board is grounded has been described, but it is of course possible to perform grounding between connectors.

Effects of the invention As explained above, according to the grounding structure of the shielded flat cable of this invention, since the cable clamp is equipped with a single conductive grounding plate, the cable can be grounded at the same time as the cable clamp. No special work required. Moreover, the connection can be made through a low impedance path.

Furthermore, in the case of a general flat cable without a shield layer, only an insulating cap is used as a cable clamp, and the connector of the flat cable can be shared regardless of the presence or absence of a shield layer.

[Brief explanation of the drawing]

1 and 2 are diagrams showing one embodiment of the present invention. FIG. 1 is a perspective view showing the grounding structure of a shielded flat cable in an exploded state, and FIG. 2 is an assembled view of the grounding structure of the shielded flat cable. Perspective view showing the state, Figures 3 and 4
The figure shows a conventional example, Figure 3 is a plan view illustrating the grounding structure of a shielded flat cable that is grounded by drawing out the drain wire, and Figure 4 is a shield that is grounded by a connector. FIG. 3 is a plan view illustrating the grounding structure of the attached flat cable. 1... Insulating housing, 3... Insulating block,
6... Insulating cap, 8... Holding part, 9... Contact part, 10... Shield exposed part, 12... Terminal part,
13... Conductive grounding plate, 21... Conductive wire, 22...
Insulating coating, 23...shielding layer.

Claims (1)

[Scope of utility model registration request] In the grounding structure of a shielded flat cable in which an insulating coating is provided around a plurality of conductor groups and a cable having a shield layer on the outside is folded back and clamped, the conductive cable is clamped by sandwiching the shield layer 23. A grounding plate 13 is provided, and the conductive grounding plate includes a contact portion 9 that presses against the exposed shield portion 10 of the shield layer, and a locking piece 11 that presses the contact portion against the shield layer and is locked to the connector.
A grounding structure for a shielded flat cable, characterized in that it has a terminal portion 12 connected to a grounding point.