JPH046132Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to an electrical connection structure, and particularly to an electrical connection structure that simultaneously fixes electrical components such as printed wiring boards to a case and electrically conducts them. .

[Problems to be solved by conventional techniques and ideas]

This type of structure will be explained based on FIGS. 4 and 5.

FIG. 4 shows a structure for fixing vehicle meters and a wiring board provided corresponding thereto.

In the figure, first and second wiring boards 2 and 3 related to instruments are placed on both sides of a case 1 made of synthetic resin (electrically insulating).
The inner unit 4 of the instrument is attached to the lower position in the figure. The first and second wiring boards 2 and 3 are fixed to the upper and lower surfaces of the case 1 by screws 5 passing through the screw through holes 1a of the case 1, and are electrically connected to each other by conductive screws 5. Ru.

Specifically, the screw 5 is electrically connected to the circuit on the first wiring board 2 via a conductive washer 6 and a conductive spring washer 7, while being electrically connected to the circuit on the second wiring board 3. Conductivity is established with the second wiring board 3 by screwing with the electrically conductive terminal plate 8,
The first and second wiring boards 2 and 3 are connected by screwing the screws 5.
It is fixed to the case 1 by holding the case 1 between the two.

By the way, in the above electrical connection structure, the arrow f in FIG.
If vibrations and stress are applied for a long time in the direction shown by, the case 1, washer 6, terminal plate 8, etc. may be deformed as shown in FIG. Since such deformation causes the electrical connection between the first and second wiring boards 2 and 3 to become unstable, conventionally a spring washer 7 is interposed as shown in FIG. Spring washer 7 as shown in the figure
The attempt is made to maintain the conductive state by stretching the .

However, in the above structure, when the spring washer 7 expands, the contact between the screw 5 and the washer 6 and the upper and lower surfaces of the spring washer 7 changes from surface contact to line or point contact, so the contact area becomes smaller. The contact resistance at that part becomes large. Therefore, when such a structure is used for a signal transmission path using a minute current, the operation of the electric circuit becomes extremely unstable.

The present invention has been made in view of the above points, and aims to provide a highly reliable electrical connection structure with stable electrical continuity.

[Means for solving problems]

In order to achieve the above object, the present invention is characterized by a structure in which a thin part such as a groove or a hole is formed near the screw through hole of a case in which the screw through hole is bored, and elasticity is imparted to the screw through hole.

〔Example〕

An embodiment of the present invention will be described based on FIGS. 1 to 3.

In FIG. 1, the structure for fixing the first and second wiring boards 2 and 3 to the case 1 using screws 5, washers 6, spring washers 7, and terminal plates 8 is the same as the conventional structure.

The features of the embodiment of the present invention reside in the thin wall portion 1b and the hole 1c provided in the case 1.

As can be seen from the cross-sectional view of FIG. 1 and the plan view of FIG.
In the semicircular part around the screw through hole 1a, a semicircular groove is provided on the upper and lower surfaces of the case 1 to form a thin wall part 1b, and in the remaining semicircular part, a hole 1c is formed along the circumferential direction. It's summery.

With this configuration, the case 1 is supported only by the thin part 1b in the vicinity of the screw through hole 1a, and is movable up and down due to the presence of the hole 1c, so it is given elasticity (flexibility), and this part is Even if stress or vibration is applied in the direction (longitudinal direction of the screw), the elasticity of the case 1 itself absorbs this, and vibrations etc. are not directly applied to the spring washer 7 or the terminal plate 8, etc. Therefore, the spring washer 7 will not expand significantly as shown in FIG.

3a, b, and c illustrate the vibration absorption effect of the elasticity of the case 1, and show that the vicinity of the screw through hole 1a is movable up and down using the thin wall portion 1b as a fulcrum.

[Effect of idea]

The present invention is as described above, and the stress and vibrations are absorbed by the elasticity of the case 1 itself, and the expansion of the spring washer is suppressed.

Therefore, since the contact of the spring washer generally maintains surface contact, the contact resistance in this portion is small, and the electrical continuity between the first and second wiring boards can be made stable.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a plan view of the main part, FIGS. FIG. 5 is a sectional view illustrating the operation in the conventional example. 1... Case, 1a... Screw through hole, 1b...
Thin wall portion, 2...first wiring board, 3...second wiring board, 5...screw.

Claims (1)

[Claims for Utility Model Registration] First and second electrical components are arranged on both sides of an insulating case, and the first and second electrical components are fixed to the case with screws that pass through the case. In the case described in 2, which electrically conducts the electrical components, a thin walled part such as a groove or a hole is formed around the screw through hole in a case in which the screw through hole is drilled, and elasticity is imparted to the screw through hole. Characteristic electrical connection structure.