JPH0357587B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrical contact pin, and more particularly to an electrical contact pin having an intermediate mounting portion for mechanically securing and electrically connecting to a through-hole portion of a printed circuit board.

[Conventional technology]

Conventionally, this type of electrical contact pin, as shown in FIGS. 4A and 4B, has a tip portion 1, an insertion taper portion 2, and an intermediate mounting portion 3 that is fitted and fixed into a through-hole portion of a printed circuit board. Triangular groove portions 4 are provided on two mutually opposing surfaces adjacent to the diagonal corner portion 5 of the intermediate mounting portion 3, extending to a position past the insertion taper portion 2. The grooves 4 are alternately arranged opposite to each other. A chamfer 6 is formed on the diagonal corner of the intermediate attachment part 3 that is different from the corner part 5.

[Problem that the invention seeks to solve]

In such a conventional electrical contact pin, the corner portion 5 of the intermediate mounting portion 3 has elasticity in the diagonal direction due to the function of the groove portion 4, as shown in FIG. 4C.
It is possible to accommodate to some extent differences in the inner diameter of the through-hole portion 23 to be inserted. but,
The inner diameter of the through hole in printed circuit boards for high-density mounting, such as computers, is usually 0.8 mm or less, and while there will be a demand for smaller diameters in the future, other electronic devices still have a diameter of 1.1 mm. Because a through-hole with a large inner diameter is required,
What is needed is an electrical contact pin that can accommodate a wider range of through-hole inner diameter differences. but,
In the conventional electric contact pin as described above, the contact force with the through-hole part and the corner part 5 of the intermediate mounting part 3
Due to the diagonal displacement of the through-hole, there is a limit to the range of the internal diameter of the through-hole that can accommodate this, resulting in the disadvantage that two types of electrical contact pins, one for a small diameter and one for a large diameter, must be prepared.

In addition, the groove portion 4 is extended to a position past the insertion taper portion 2 so that the insertion taper portion 2, which first contacts the through-hole portion 23, also has elasticity in the diagonal direction. The wall thickness between the tapered part 2 and the groove part 4 is thin, and there is a drawback that it is easy to break when external force is applied.

In addition, the groove 4 of the electrical contact pin constructed in this way is usually formed by pressing only once, but this method does not have good dimensional accuracy, making it difficult to obtain the necessary dimensions, and the resulting electrical There was a drawback that the insertion force into the through hole, contact performance, and holding force varied depending on the contact pin.

[Means for solving problems]

The present invention includes a tip portion inserted into a through-hole portion of a printed circuit board, an intermediate mounting portion that contacts and is fixed to the through-hole portion, and a diameter increasing from the tip portion toward the intermediate mounting portion. and an insertion taper portion having a sloped surface, the insertion taper portion being adjacent to a diagonally first corner portion of the intermediate attachment portion on two opposing surfaces of the intermediate attachment portion. a groove portion extending to the middle of the first corner portion; an expanded groove portion formed to widen the opening width of at least a portion of the groove portion so that the diagonal length between the first corner portions becomes longer; and a groove portion that is different from the first corner portion. a chamfer provided at a second diagonal corner portion and formed so as to shorten the diagonal length between the second corner portions, and an arm-shaped portion forming the first corner portion; It is characterized in that the wall thickness is thinner than the wall thickness of the inter-groove connecting portion that connects the arm-shaped portions.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

1A and 1B showing an embodiment of the present invention
Referring to the figure, the electrical contact pin 31 of the present invention includes:
A tip part 7 that is inserted into a through-hole part of a printed circuit board, an intermediate mounting part 9 that is fixed by contacting the through-hole part, and an inclined surface whose length increases from the tip part 7 toward the intermediate mounting part 9. It has an insertion tapered portion 8. Diagonal corner part 1 from the intermediate mounting part 9 to the middle of the insertion taper part 8
Grooves 10 that alternately face each other are provided on two opposing surfaces adjacent to the thin part 2, and a part of the center of the groove 10 is an expanded groove 11 having an opening wider than the thin part 10. Moreover, a chamfer 13 is provided on a diagonal corner portion of the intermediate attachment portion 9 that is different from the corner portion 12 . The expansion groove 11 provided in a part of the groove 10 expands the range of diagonal displacement of the intermediate attachment part 9, so that a wider range of through-hole inner diameters can be accommodated. That is, as shown in FIG. 1B, the diagonal length between the two corner portions 12 is formed long, the diagonal length between the two chamfers 13 is formed short, and furthermore, the diagonal length between the two corner portions 12 is formed short.
The wall thickness x of the arm-shaped portion 15 forming the groove is considerably thinner than the wall thickness y of the inter-groove connecting portion 16 between the two expansion groove portions 11. As a result, arm-shaped portion 1
5 has flexibility, and the diagonal length between the corner portions 12 can be varied over a wide range. When this electrical contact pin is inserted into the through-hole, the corner portion 12 comes into contact with the through-hole and receives a pressing force in the directions of arrows A and B, causing the arm-shaped portion 15 to deform. to make sure it sticks to the through-hole part. Here, the corner portion 12, which is given flexibility by the expansion groove portion 11, comes into active contact with the through-hole portion due to the chamfer 13, and deformation due to the pressing force from the through-hole portion is promoted. .
Furthermore, since the groove portion 10 is provided only up to the middle of the insertion taper portion 8, if the position where the insertion taper portion 8 first contacts the through-hole portion is a position where the groove portion 10 is not provided, the insertion taper portion 8 does not have sufficient elasticity and may damage the through-hole section. In order to prevent this, the facing portion 14 is provided in the insertion taper portion 8 so that the position where it first comes into contact with the through-hole portion is at a position where it has flexibility due to the action of the groove portion 10. However, this imposition portion 14 is different from the insertion taper portion 8.
It is not necessary to provide this if the part that first comes into contact with the through-hole part has sufficient elasticity.

To obtain the electrical contact pin 31 as described above, first press the two opposing sides of the electrical contact pin with a coining punch 15 as shown in FIG. 2A to form the groove 1.
0, and then expanding a part or all of the groove 10 using an expansion punch 16 as shown in FIG. 2B. Forming the expanded groove portion 11 by double pressing in this manner has the advantage that the necessary diagonal dimensions can be obtained with high precision.

In addition, as shown in FIG. 3, if the same printed circuit board 20 includes through-holes 21 and 22 of different diameters, all the electrical contact pins connected by the carrier 17 in the first step are The groove 10 is formed with the coining punch 15, and in the subsequent second step, for example, a counter and a press machine are connected, and the electrical contact pin on which the groove 10 is formed is selected according to the inner diameter of the corresponding through-hole. By specifically forming the expansion groove portion 11 by pressing with the expansion punch 16, it is possible to coexist the electric contact pin 30 having only the groove portion 10 and the electric contact pin 31 having the expansion groove portion 11 on the same carrier 17.

Furthermore, the surfaced portion 14 of the insertion tapered portion 8 is provided so that the outer diameter on the diagonal of the insertion tapered portion 8 at that position is approximately equal to or slightly smaller than the inner diameter of the through-hole portion 21 having the minimum inner diameter. For example, no damage is caused to the through-hole portion of any inner diameter during insertion.

〔Effect of the invention〕

As explained above, in the present invention, at least a part of the groove provided in the intermediate mounting part of the electrical contact pin is an expanded groove having an opening width wider than this groove, and the intermediate mounting part is connected to the through-hole part of the printed circuit board. By increasing the outer diameter of the diagonal corner portions that come into contact, it is possible to obtain a single type of electrical contact pin that can be applied to through-hole portions with a wider range of inner diameters.

[Brief explanation of drawings]

FIG. 1A is a perspective view of an embodiment of the present invention; FIG. 1B is a perspective view of an embodiment of the present invention;
The figure is a sectional view of the intermediate mounting part in Figure 1A,
Figure C is a cross-sectional view showing the state of insertion into the through-hole portion of the same embodiment, Figures 2A and 2B are perspective views of the coining punch and expansion punch, respectively, and Figure 3 shows the electric contact pin connected by a carrier. FIG. 4A is a perspective view of a conventional electrical contact pin, FIG. 4B is a cross-sectional view of the intermediate mounting portion in FIG. 4A, and FIG. 4C is FIG. 4A. FIG. 3 is a cross-sectional view of the electrical contact pin inserted into the through-hole portion of the printed circuit board. DESCRIPTION OF SYMBOLS 1... Tip part, 2... Insertion taper part, 3... Intermediate attachment part, 4... Groove part, 5... Corner part, 6... Chamfering,
7... Tip part, 8... Insertion taper part, 9... Intermediate mounting part, 10... Groove part, 11... Expansion groove part, 12... Corner part, 13... Chamfering, 14... Chamfering part, 15... Coining punch, 16... Expansion punch , 17... carrier, 20... printed circuit board, 21, 22, 23...
Through hole part, 30, 31...electrical contact pin.

Claims (1)

[Scope of Claims] 1. A tip portion inserted into a through-hole portion of a printed circuit board, an intermediate attachment portion that contacts and is fixed to the through-hole portion, and a diameter extending from the tip portion toward the intermediate attachment portion. an electrical contact pin having an insertion taper portion having an inclined surface provided to increase in size, and adjacent to a diagonally first corner portion of the intermediate attachment portion on two opposing sides of the intermediate attachment portion; a groove provided to the middle of the insertion taper portion; an expanded groove formed by widening the opening width of at least a portion of the groove so that a diagonal length between the first corner portions becomes longer; and the first corner portion; an arm forming the first corner portion, and comprising: a chamfer provided at a second diagonal corner portion on a different side and formed so as to shorten a diagonal length between the second corner portions; An electrical contact pin characterized in that the wall thickness of the arm-shaped portion is formed to be thinner than the wall thickness of the inter-groove connection portion that connects the arm-shaped portion. 2. The electrical contact pin according to claim 1, characterized in that the insertion taper portion is provided with a surfaced portion whose outer diameter is equal to or less than the inner diameter of the minimum diameter through-hole portion to be inserted. Electrical contact pin.