JPH0227592Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a printed circuit board mounting device for dustproofing electronic equipment.

[Background of the idea]

An example of a conventional printed circuit board mounting apparatus of this type is shown in FIG. 3. That is, 1 is a printed circuit board, and this printed circuit board 1
In addition to electrical components such as resistors, capacitors, and integrated circuits, the upper surface 11 is provided with electrical components 2 such as a time meter or other printed circuit boards. A hole 14 is drilled through which a long-legged fixing bolt 3 fixed integrally passes. Reference numeral 4 denotes a case that houses a unit consisting of the printed circuit board 1, electrical components 2, etc., and a bottom wall 4 provided at the bottom of the case 4.
An annular standing portion 42 is formed on the inner peripheral edge of the printed circuit board 1 , and a stepped portion 43 for receiving the peripheral edge 13 of the printed circuit board 1 is formed on the inner side of the upper side edge of the standing portion 42 .
is formed. Also, the upright portion 4 of the bottom wall 41
A through hole 44 for the bolt 3 is bored inside the bolt 2, and a boss portion 45 is integrally formed around the upper side of the through hole 44.
5 is a nut screwed onto the bolt 3 for fixing the electrical component 2 to the printed circuit board 1; 6 is a nut for fixing the printed circuit board 1 to the bottom wall 41 of the case 4; and 7 is the printed circuit board. This is an electrical connector attached to the lower surface of the case 4 and exposed to the outside of the case 4 through an opening 49 provided in the bottom wall 41 of the case 4. When fixing the printed circuit board 1 to the case 4 to which the electrical component 2 is fixed by the bolt 3 and nut 5, after passing the protrusion of the bolt 3 into the through hole 44 of the case 4, Screw the bolt 6 into the protruding tip of the bolt 3, and
This is how the nut 5 of No. 2 is received by the boss portion 45.
The printed circuit board 1 is fixed to the case 4 almost in parallel, and the peripheral edge 13 of the printed circuit board 1 is
A connector opening 49 is provided in close contact with the stepped portion 43.
Dust entering the case 4 from electrical parts 2
This prevents it from penetrating into the sides.

However, in such a conventional mounting structure between the case 4 and the printed circuit board 1, the central portion of the printed circuit board 1 is connected to the boss portion 4 through the nut 5.
5 and the peripheral edge 13 of the printed circuit board 1 is received by the step 43. Therefore, the closeness between the peripheral edge 13 of the printed circuit board 1 and the step 43 depends on the height of the boss 45 and the nut 5. will be done. Therefore, in reality, the degree of closeness changes due to an error in the height dimension of the nuts 5 or insufficient tightening of the nuts 5. For example, if even one nut 5 is taller than the others, the peripheral edge 13 and A gap is created between the edge part 13 and the step part 43, which deteriorates the dust-proofing properties.If the height of the nut 5 is low, the printed circuit board 1 is attached with a curved support.
Due to the bending stress, as the closeness with the
There was a problem that the printed circuit board 1 could be damaged.

[Purpose of invention]

The present invention has been made in order to solve this problem, and has a boss portion on the inner surface of the bottom wall of the case that has a recess in the center for loosely fitting the nut 5 for fixing the electrical component and directly receives the lower surface 12 of the printed circuit board 1. 46, the case and printed circuit board 1 can be easily connected without being affected by the dimensional accuracy or tightening accuracy of the nut.
It is an object of the present invention to provide a printed circuit board mounting device that can bring the two into close contact with each other in a dust-proof manner.

[Example of idea]

The present invention will be explained in detail below based on the embodiment shown in FIGS. 1 and 2. This embodiment has a feature in the structure of the boss part, and the other structures are different from those shown in the conventional example. Since they are the same, the same structural parts are given the same reference numerals as in the conventional example, and the structural description thereof will be omitted.

That is, the boss portion 46 in this embodiment protrudes above the bottom wall 41 of the case 4, as in the conventional example, but the upper surface 47 of this boss portion 46 is similar to the step portion 43.
In addition, a recess 48 (see FIG. 2) for loosely fitting a nut is formed concentrically with the through hole 44 in the center of the boss 46.

The above is the main structure of this embodiment. In order to fix the printed circuit board 1 inside the case 4, first, as explained in the conventional example, the electrical components 2 arranged on the printed circuit board 1 are attached to the bolts 3. and nuts 5, then insert the bolts 3 protruding from the lower side of the printed circuit board 1 into the through holes 44 of the case 4.
After passing through the bolt 3, the nut 6 is screwed onto the protruding tip of the bolt 3, and the nut 5 is tightened, so that the lower side of the printed circuit board 1 comes into contact with the upper surface 47 of the boss part 46 and the step part 43. However, at this time,
The nut 5 that fixes the electrical component 2 to the printed circuit board 1 is located in the recess 48 of the boss 46, so that when the nut 6 is tightened, the lower surface of the printed circuit board 1 is brought into contact with the upper surface of the boss 46. 47 and the stepped portion 45, and as a result, the dustproof property inside the case is improved.

[Summary of the idea]

As described above, the present invention integrally fixes the long leg fixing bolt 3 to the electrical component 2 to be placed on one side 11 of the printed circuit board 1, and also allows the fixing bolt 3 to be inserted into the printed circuit board 1. The fixing bolt 3 is inserted into the through hole 14 so that the printed circuit board 1 is held between the fixing bolt 3 exposed from the other surface 12 of the printed circuit board 1. Electrical component fixing nut 5
The electrical component 2 is fixed on one surface 11 of the printed circuit board 1 by screwing the electrical components 2 together, and the printed circuit board is further fixed on the printed circuit board mounting wall 41 of the case 4 in which the printed circuit board 1 is housed. A stepped portion 43 against which the peripheral edge 13 of the printed circuit board 1 is brought into contact, a connector opening 49 for taking out the electrical connection connector 7 fixed to the other surface 12 of the printed circuit board 1, and the fixing bolt 3. The stepped portion 4 has a through hole 44 through which the electrical component fixing nut 5 is inserted, and a recess 48 into which the electrical component fixing nut 5 is loosely fitted.
A boss portion 46 set at the same height as 3 is provided,
The fixing bolt 3 is inserted into the through hole 44 of the boss portion 46 and is exposed to the outside of the case 4. This is a printed circuit board mounting device characterized in that the printed circuit board 1 is fixed tightly onto the stepped portion 43 in the case 4 by screwing together a nut 6.

[Effect of idea]

Therefore, according to this printed circuit board mounting device, when the printed circuit board 1 is fastened with the bolt 3 and the nut 6, the step portion 43 and the upper surface 47 of the boss portion 46 formed on the mounting surface are at the same height. Since the lower surface of the printed circuit board 1 is brought into close contact with the case 4,
The dustproofness of the space on the side of the electrical components 2 inside can be improved, and since the contact pressure acting on the printed circuit board 1 is uniformly applied at various places, the vibration resistance of the printed circuit board 1 after installation is improved. Furthermore, there is an effect that the printed circuit board 1 can be mounted without being distorted.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the printed circuit board mounting apparatus according to the present invention, FIG. 2 is an enlarged sectional view of the main part thereof, and FIG. 3 is a sectional view of a conventional example. 1... Printed circuit board, 11... Top surface, 12... Bottom surface,
13... Peripheral part, 2... Electrical component, 3... Fixing bolt,
4... Case, 41... Bottom wall, 42... Annular standing portion, 4
3...Step part, 44...Through hole, 46...Boss part, 47...
Top surface of boss portion, 48... recess, 49... opening for connector, 5, 6... nut, 7... connector for electrical connection.

Claims (1)

[Scope of utility model registration request] A long fixing bolt 3 is integrally fixed to the electrical component 2 to be placed on one surface 11 of the printed circuit board 1, and a through hole 14 is formed in the printed circuit board 1 through which the fixing bolt 3 is inserted. Then, insert the fixing bolt 3 into the through hole 14 and screw the electrical component fixing nut 5 so as to clamp the printed circuit board 1 onto the fixing bolt 3 exposed from the other surface 12 of the printed circuit board 1. The electric component 2 is fixed on one surface 11 of the printed circuit board 1 by fitting the electrical component 2, and the printed circuit board mounting wall 4 of the case 4 in which the printed circuit board 1 is housed is fixed.
1, a stepped portion 43 against which the peripheral edge 13 of the printed circuit board 1 comes into contact, and the other surface 1 of the printed circuit board 1.
A connector opening 49 for taking out the electrical connection connector 7 fixed to the electrical connection connector 2 and a through hole 44 through which the fixing bolt 3 is inserted are formed, and the electrical component fixing nut 5 is loosely fitted. A boss portion 46 having a concave portion 48 and a boss portion 46 set at the same height as the step portion 43 is provided, and the fixing bolt 3 is inserted into the through hole 44 of the boss portion 46 to the outside of the case 4. By screwing the printed circuit board fixing nuts 6 onto the exposed fixing bolts 3 so as to clamp the printed circuit board mounting wall 41 of the case 4, the printed circuit board 1 is fixed to the step part in the case 4. 4. A printed circuit board mounting device, characterized in that the printed circuit board mounting device is fixed tightly onto a printed circuit board.