JPH05299856A - Structure mounting device for plastic case - Google Patents

Abstract

PURPOSE:To provide a boss which withstands a clamping torque of a screw without increasing in thickness a tall boss or without attaching a support in a structure mounting device for mounting a structure by using the screw at an end of the relatively high boss protruding from a plastic case. CONSTITUTION:A diameter of a hole of a boss 2 is formed in two steps. A lower hole 4 of a screw is formed at a root of the boss, its upper hole 8 is formed in a diameter for merely passing the screw, and a clamping torque of the screw is received by the boss and a plastic case body. Accordingly, even the high boss 2 may not be increased in thickness and not be provided with a support, and a rear surface of the boss 2 may be formed in a designing surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting device for mounting a structure such as a printed circuit board on a plastic case.

[0002]

2. Description of the Related Art FIG. 3 is a cross-sectional view of a conventional plastic case when a structure such as a printed circuit board is fixed at a position where the height of a boss is required to some extent.
FIG. 3A is a plan view and a perspective view of only the boss portion. In the figure, 1 is a plastic case main body, 2 is a relatively high boss protruding from the case main body, 3 is a supporting portion for supporting the boss because the boss is high, 4 and 5 are under screws formed in the boss 2. It is a hole and a meat hole for distortion prevention. Then, the printed board 6 is fixed to the boss 2 using the P tight screw 7.

The conventional mounting of this type is constructed as described above, and since the printed circuit board and the like are tightened with the P tight screw, a torsion moment is applied to the boss and the boss body 2 is cracked when it is thin, so it is necessary to thicken the boss body. There is
Also, a support 3 for reinforcement was necessary.

[0004]

In the boss having the above-described shape, it is necessary to make the diameter of the boss main body thick enough to allow the tightening torque of the screw, and also support is required. It had the drawback of being complicated. Further, when molding plastic, if the plastic thickness is not uniform, distortion will occur during molding. Therefore, as shown in FIG. 3, a machined hole is formed on the opposite side of the pilot hole of the screw to prevent distortion. However, there is a drawback that the surface of the plastic case cannot be used as a design surface.

The present invention has been made in order to solve the above problems, and obtains a mounting device which does not increase the thickness of the boss body even with a high boss, and which does not require a support for the boss or a thinned portion. The purpose is to

[0006]

In the plastic case according to the present invention, the hole diameter of the high boss is set in two stages, the prepared hole of the screw to be screwed is set close to the case body, and the moment due to the tightening torque of the screw is set. Both the case body and the boss are received, and the hole at the top is made larger in diameter than the screw so that the boss acts as a spacer.

[0007]

In the plastic case configured as described above, the moment caused by the screw tightening torque is received not only by the boss but also by the case body, so that the boss can be made thin and the support can be eliminated. Also, since the pilot hole of the screw can be made up to the plastic thickness of the case body, the plastic thickness can be made uniform to some extent without special work, so a high boss can be made on the back side of the design surface as well. ..

[0008]

EXAMPLES Example 1. FIG. 1 is a cross-sectional view showing an embodiment of the present invention. In the figure, 1 is a plastic case body, 2 is a boss, and this boss is provided with two stages of holes 4 and 8 having different hole diameters. Reference numeral 4 denotes a prepared hole formed near the case, 8 denotes a hole diameter larger than that of a relatively long screw 9, and the upper portion of the boss is a through hole having a structure serving as a spacer.

In the plastic case constructed as described above, as shown in FIG. 1, a long screw 9 is used, and the screw 9 is screwed into the pilot hole 4 of the screw, and the printed circuit board 6 is attached to the boss 2. Fix it. According to this method, the moment due to the tightening torque of the screw 9 is received by the lower portion of the boss 2 and the case body 1, and the upper portion of the boss is not subjected to the force in the twisting direction by the screw 9, so that the boss is thick. The thickness can be reduced, and the conventional support is not required, and the mold can be simplified. Further, since the pilot hole 4 of the screw can be dug up to the thickness of the plastic case body 1, the surface of the plastic case can be used as a design surface. Needless to say, the printed circuit board may be another structure.

Embodiment 2. In the above embodiment, the boss 2 is provided with the pilot hole 4 for the screw, and the long P-tight screw 9 is used to stop the printed circuit board 6. However, as shown in FIG. It is possible to obtain the same effect by embedding and stopping with the pan screw 11.

[0011]

As described above, according to the present invention, by supporting the moment due to the tightening torque of the screw at the lower part of the boss, the boss can be made thin and the support can be eliminated, and the mold can be simplified. Further, since the pilot hole of the screw can be dug up to the thickness of the plastic case, there is an effect that the back surface of the high boss can be made a design surface.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing Embodiment 2 of the present invention.

FIG. 3 is a cross-sectional view showing a conventional mounting device of this type.

FIG. 4 is a plan view showing a structure of a conventional boss portion.

FIG. 5 is a perspective view showing a structure of a conventional boss portion.

[Explanation of symbols]

 1 plastic case 2 boss 4 pilot hole of screw 6 printed circuit board 8 through hole 9 screw 10 embedded screw seat

Claims (2)

[Claims] 1. A structure in which a structure is attached by passing a screw through a hole formed in a boss portion projecting on the inner surface of a plastic case, wherein the hole diameter of the boss is two stages, and the prepared hole of the screw is a case main body. A structure mounting device in a plastic case, characterized in that it is formed in the immediate vicinity of, and the diameter of the hole in the upper part is thicker than the screw. 2. The structure mounting device for a plastic case according to claim 1, wherein a screw seat into which a screw is screwed is embedded in the prepared hole portion at the base of the boss.