JP2837391B2 - Resin case fitting structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin case fitting structure for sandwiching and holding a printed circuit board used for an electronic device or the like between resin cases.

[0002]

2. Description of the Related Art Hitherto, when a printed circuit board is housed in a housing such as a resin case, a structure for sandwiching and holding the printed circuit board between upper and lower resin cases has been widely used because it is inexpensive and can be easily attached. FIG. 4 is an exploded perspective view showing a conventional resin case fitting structure, and FIG. 5 is a cross-sectional view showing a conventional resin case fitting structure. 6A and 6B are partial cross-sectional views showing a conventional fitting structure. FIG. 6A is a view showing a method of holding a substrate in a vertical direction, FIG. 6B is a detailed view of a case fitting claw portion, FIG. 6C is a diagram illustrating a method of holding the substrate in the horizontal direction.

In a general fitting structure of a resin case, a printed circuit board 1 on which electronic components and the like are mounted is held so as to be sandwiched between an upper case (lid) 2 and a lower case (body) 3 made of resin. It has a structure. The lid 2 has a main body 3
There are provided a plurality of fitting holes 4 for fitting into the vicinity of the edge of the lower opening. Further, a plurality of board holding portions 5 for holding the printed board 1 from above are protruded from the inner wall of the lid 2. The main body 3 is provided with the same number of fitting claws 6 as the fitting holes 4 at positions corresponding to the fitting holes 4 to be fitted into the fitting holes 4 of the lid 2. Further, a plurality of board receiving portions 7 for receiving the printed board 1 from below are protruded from the inner wall of the main body 3. In addition, the shape of the printed circuit board 1,
The dimensions are matched to the inner wall of the main body 3, and positioning in the front, rear, left and right directions is performed.

Then, the printed board 1 is vertically moved (vertically) by the cover 2, the board holding section 5 of the main body 3, and the board receiving section 7.
The printed board 1 is slightly bent while being sandwiched from the direction, and the printed board 1 is fixed by the reaction force of the printed board 1 (FIG. 6A). In addition, by adjusting the end surface of the printed circuit board 1 to the inner wall of the main body 3, rattling in the front, rear, left and right (horizontal) directions is suppressed, and the fitting holes 4 and the fitting claws 6 are fitted (FIG. 6B). The printed circuit board 1 is housed in a resin case by connecting the lid 2 and the main body 3 (FIG. 6C).

[0005]

However, in holding the printed circuit board 1 using the reaction force, it is necessary to increase the reaction force in order to firmly fix the printed circuit board 1. For this reason, the warpage of the printed circuit board 1 increases, and a stress is generated in the soldered portion of the mounted component, which may cause a solder crack or the like. Holding and positioning in the front-rear horizontal direction by aligning the end surface of the printed circuit board 1 with the inner wall of the main body 3 leads to deterioration of insertability due to the finished dimensions of the resin case and the printed circuit board 1 and generation of chattering noise due to rattling. There is a problem.

An object of the present invention is to solve the above problems.

[0007]

SUMMARY OF THE INVENTION The present invention solves such a problem. In a resin case fitting structure in which a printed circuit board is sandwiched and accommodated by a resin case composed of a main body and a lid, the present invention relates to: A rib formed on the inner wall and having a slope such that the insertion direction side of the printed board protrudes, and a protrusion provided on the lid body portion, the printed board being pressed against the sloped portion of the rib by the protrusion, It is characterized by regulation.

Further, an engaging portion comprising a hole and a claw is formed in the main body portion and the lid portion, and an engaging surface between the hole and the claw of the engaging portion separates the main body portion and the lid portion. A gradient is provided such that when a force is applied in the direction, the engagement force between the hole and the claw increases. The claw is provided on the main body, and the rib is provided on an inner surface of the case of the claw.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a fitting structure of a resin case according to one embodiment of the present invention, and FIG. 2 is a perspective view showing a fitting structure of a resin case according to one embodiment. A resin case for protecting the printed circuit board 11 on which electronic components and the like are mounted is formed in a box shape by an injection molding method or the like, and is divided into an upper case (lid) 12 and a lower case (main body) 13 so as to be divided. Are held so as to be sandwiched.

The main body 13 has an engaging claw 16, a board receiving portion 17, and a rib 18. The engagement claw 16
It is for engaging the main body 13 and the lid 12, and a plurality of protrusions are provided on the outer periphery of the opening end face of the main body 13,
It is formed in a beak shape outward (a sloping claw with the lower side expanding). The board receiving portion 17 supports the printed board 11 from below, and is provided on the bottom surface of the main body 13 so as to protrude along the inner wall. The rib 18 is provided on the inner surface side of the engaging claw 16, and has a slope such that it is thicker at the bottom and becomes thinner as it goes upward (a slope that becomes thicker in the insertion direction of the printed circuit board 11). The printed circuit board 11
The outer dimension of the printed circuit board 11 is large enough to have a slight clearance with the inner wall of the main body 13 in the state of being inserted into the main body 13, so that the end surface of the printed circuit board 11 comes into contact with the sloped portion of the rib 18 so as to stop the front, rear, left and right movement. Is formed.

The lid 12 is provided with an engagement hole 14 and a substrate pressing portion (projection) 15. The number of the engagement holes 14 is for the engagement of the engagement claws 16 of the main body 13, and the number of the engagement holes 14 is provided in the vicinity of the edge of the opening of the lid body 12 corresponding to the number of the engagement claws 16. The engagement hole 14 is hollowed out in a square shape. The engaging surface 14 of the engaging hole 14 and the engaging claw 16
1, 161 is provided with a gradient such that the left side in the figure becomes lower. The board holding part 15 holds the printed board 11 supported from below by the board receiving part 17 while holding the printed board 11 from above, and a plurality of the board holding parts 15 are protruded from the inner wall of the lid part 12.

Next, an operation of assembling the resin case by the fitting structure will be described. First, the main body 13 of the resin case
The printed circuit board 11 on which electronic components and the like are mounted is inserted and placed through the upper opening. Then, the end surface of the printed circuit board 11 comes into contact with the inclined portions of the plurality of ribs 18 and stops. Then, cover the main body 13 with the opening of the lid 12 facing downward, and push the plurality of engaging claws 16 into engagement with the engaging holes 14. Then, the board holding part 15 of the lid part 12 is brought into contact with the rib 18 of the main body part 13 and the printed board 11 being stationary.
Press down on the upper surface of. As a result, the printed board 11 is pressed by the board holding portion 15 from the upper surface, is pressed down until it comes into contact with the board receiving portion 17, and is fixed at a predetermined position. At this time, the printed circuit board 11 or the rib 18
However, they are slightly crushed at the abutting portion, and both are pressed.

As described above, in this embodiment, by setting the rib 18 having the inclined surface, the end face of the printed circuit board 11 bites into the rib 18 at a plurality of places and is pressed. ), And the vibration resistance is improved. Therefore, in the case of a device incorporating a component that generates vibration, for example, a notification device or the like (buzzer or the like), the vibration of the printed circuit board 11 due to the vibration generating component is eliminated, and the generation of abnormal noise or the tone of the notification device changes. Can be prevented.

Further, since the backlash of the printed board 11 is eliminated, the amount of pressing of the board holding portion 15 can be reduced, and the warpage stress of the printed board 11 can be reduced.
In addition, as shown in FIG. 3, the slopes of the engagement claws 16 and the engagement surfaces 161, 141 of the engagement holes 14 are provided, so that arrows A,
When a force in the direction A '(a force pulling the resin case up and down) is applied, a force in the directions indicated by arrows B and B' (a force in the direction in which the engaging claw 16 and the engaging hole 14 are engaged) is generated. The fitting force of the case is improved. When the printed board 11 is fixed at a predetermined position by providing the rib 18 inside the engaging claw 16, the rib 18 is pushed in the direction of arrow C by the end surface of the printed board 11, and the engaging claw 16 is It is pushed outward (in the direction of arrow C) together with the rib 18, and the fitting force between the engaging claw 16 and the engaging hole 14 is improved.

[0015]

As described in detail above, in the fitting structure of the resin case according to the present invention, the printed board is pressed and fixed to the sloping rib provided on the main body. The printed circuit board can be fixed without rattling, and the amount of pressing of the printed circuit board can be reduced, so that the warpage stress of the printed circuit board can be reduced. Further, since the engaging surfaces of the claws and holes are formed with a gradient, the fitting force of the resin case can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a fitting structure of a resin case according to an embodiment of the present invention.

FIG. 2 is a partial perspective view showing a fitting structure of a resin case according to one embodiment of the present invention.

FIG. 3 is an enlarged view showing an engagement portion (claw, hole) of the resin case according to one embodiment of the present invention.

FIG. 4 is an exploded perspective view showing a conventional resin case fitting structure.

FIG. 5 is a cross-sectional view showing a conventional resin case fitting structure.

FIG. 6 is a partial sectional view showing a conventional fitting structure.

[Explanation of symbols]

 11 printed circuit board 12 lid 13 body 14 engagement hole 15 board holder 16 engagement claw 17・ Substrate receiving part 18 ・ ・ ・ ・ Rib

Claims (3)

(57) [Claims] 1. A resin case fitting structure in which a printed circuit board is sandwiched and accommodated by a resin case composed of a main body and a lid, wherein a gradient is formed such that an insertion direction side of the printed circuit board formed on an inner wall of the main body protrudes. And a protrusion provided on the lid portion, wherein the printed circuit board is pressed against the inclined portion of the rib by the protrusion to regulate the position. 2. An engaging portion comprising a hole and a claw is formed in the main body portion and the lid portion, and an engaging surface between the hole and the claw of the engaging portion separates the main body portion and the lid portion. 2. The resin case fitting structure according to claim 1, wherein a gradient is provided such that an engagement force between the hole and the claw increases when a force is applied in the direction. 3. The resin case fitting structure according to claim 1, wherein the claw is provided on the main body, and the rib is provided on an inner side surface of the case of the claw.