JPH02100394A - Protective device for electronic control circuit - Google Patents

Abstract

PURPOSE:To improve the reliability of workability and soldering by temporarily fixing a lower case to a printed wiring board by an engaging leg. CONSTITUTION:Fixing legs 1a, 1b, 1c, 1d for an upper case 1 are fastened to the patterns 5 of a printed wiring board 3 through soldering. An engaging leg 2a for a lower case 2 has slip-off stop structure, and the engaging leg 2a is inserted into the hole 3e of the board 3, thus temporarily fixing the lower case 2 to the board 3. Consequently, when the fixing legs for the upper case 1 projected to the rear side of the board 3 and the lower case 2 are soldered, the fixing legs and the lower case 2 need not be supported at all times, thus smoothly conducting operation. The lower case 2 is fastened temporarily to the board 3 by the engaging leg 2a, thus decreasing the positions of soldering for fixing the lower case 2.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention blocks external noise that affects an electronic circuit configured on a printed circuit board (hereinafter referred to as Pvi) or unnecessary radiation noise generated from this electronic circuit. The present invention relates to a protection device for electronic control circuits equipped with a shield case.

Prior Art A conventional shield case is inserted from the front side into holes 3a, 3b, 3c, and 3d provided in a P plate 3, as shown in Fig. 4, and fixed to the pattern 5 of the P plate 3 by soldering. It is composed of an upper case l having legs 1a, lb, lc, and 1d, and a lower case 6 fixed to the back side of the P plate 3 so as to sandwich the upper case I and the P plate 3.

FIG. 5 is a state diagram when the upper case 1 and the lower case 6 are fixed to the P plate 3.

As shown in FIG. 5, the upper case l has its leg 1a.

When fixing lb, lc, and ld to the pattern 5 of the P plate 3 by soldering and fixing the lower case 6, the legs 1a of the upper case l protrude from the back side of the P plate 3.

The lb, lc, ld and the lower case 6 were connected and fixed by soldering 4.

Problem to be Solved by the Invention However, in the case of the above conventional shield case, in order to fix the lower case 6, the legs 1a, lb,
lc and ld are required at several locations to complete the connection and fixation, and it is necessary to support the lower case 6 in some way until the soldering is completed and the lower case 6 is fixed.

Furthermore, the legs 1a, lb, lc, and ld are not only hidden inside the lower case 6, but also the legs 1a, lb,
, lc, ld and the lower case 6 have a small boundary, so the solder is on the leg 1a.

It is difficult to flow between the LB, LC, LD and the lower case (lower) 6, and it is not possible to easily confirm whether the connection is complete by soldering, resulting in poor workability (and poor reliability). There were other problems.

In view of the above-mentioned conventional problems, the present invention provides a shield case for P.
The purpose is to improve workability and reliability when fixing to a board.

Means to solve the problem In order to solve the above problem, insert the P plate from the back side of the P plate.
Engagement legs for temporarily fixing the lower case to the plate and obliquely cut fixing claws for penetrating the P plate and fixing both the upper and lower cases by soldering are provided on the upper case or the lower case.

Function The present invention allows the lower case to be temporarily fixed to the P plate by the above means, and by cutting the tip of the fixed leg, which is the soldering part, diagonally to the case (upper part), the case and the fixed leg can be easily fixed. Solder can easily flow into the gaps, and it is also easier to check after soldering.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes an upper case, and fixed legs 1a are inserted from the front side into holes 3a, 3b, 3c, and 3d drilled in the P plate 3 and fixed to the pattern 5 of the P plate 3 by soldering. , lb, lc, and ld. 2 is a lower case that is paired with the upper case l, and the upper case l and the P plate 3
The engaging leg 2a is inserted from the back side into the hole 3e made in the P plate 3 so as to sandwich the above, and the upper case protrudes from the back side of the P plate 3! It has a fixed leg 1b and a fixed claw 2b for connection and fixation by soldering. The engaging leg 2a is prevented from being pulled out through the fixed leg 2b,
A bent portion 2C for temporarily fixing the lower case 2 to the P plate 3 is provided. Further, the fixing claw 2b is cut diagonally as shown in the figure.

In FIG. 2, the fixed legs 1a, 1b, lc of the upper case 1
, ld are fixed to the pattern 5 of the P plate 3 by soldering. Furthermore, the engaging leg 2a of the lower case 2 has a structure that prevents it from being removed as shown in the figure, and by inserting the engaging leg 2a into the hole 3e of the P plate 3, the lower case 2 can be attached to the P plate. 3 can be temporarily fixed.

Therefore, when soldering the fixed legs of the upper case 1 protruding from the back side of the P board 3 and the lower case 2, there is no need to support them from beginning to end, and the work can be carried out smoothly. Furthermore, since the lower case 2 is temporarily fixed to the P plate 3 by the engaging legs 2a, the number of soldering points for fixing the lower case 2 can be reduced compared to the conventional case.

Furthermore, as shown in FIG. 3, the fixing claw 2 of the lower case 2
The tip of b is cut diagonally.

As a result, the boundary between the fixed leg 1b of the upper case 1 and the fixed claw 2b becomes longer than before, so that during soldering, the solder tends to flow between the fixed leg 1b and the fixed claw 2b, and the solder The workability of attaching is improved. Further, since the fixed leg 1b is clearly visible from the outside, confirmation after soldering can be easily performed, and reliability is improved.

Effects of the Invention As described above, the engaging legs of the present invention allow the lower case to be temporarily fixed to the P plate, so there is no need to support the lower case when soldering the fixing claws to the fixing legs of the upper and lower cases. (Connections and connections with fewer soldering points than before)
Since it can be fixed and the soldering situation can be easily confirmed L2, effects such as improved workability and reliability of soldering can be obtained.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of a protective device showing an embodiment of the present invention, FIG. 2 is a front sectional view showing the shield case in the same protective device in a fixed state, and FIG. 3 is a side view showing the same fixed state. FIG. 4 is an exploded perspective view of a conventional protection device, and FIG. 5 is a half-cutaway side view showing a state in which a shield case is fixed in the protection device. l...Top case, la, lb, lc, ld...
...Fixed leg, 2...Lower case, 2a...
...Engaging leg, 2b...Fixing claw, 3...
・P temporary, 3a, 3b, 3c, 3d, 3e... hole.

Claims (1)

[Claims] A shield case for blocking external noise or unnecessary radiation noise generated from the electronic circuit is provided on a printed wiring board equipped with an electronic circuit and parts constituting the electronic circuit, and the shield case is inserted into the printed wiring board from the front and back sides of the printed wiring board. It is composed of an upper case and a lower case surrounding an electronic circuit, and at least one of the upper case or the lower case is provided with a fixing leg that penetrates the printed wiring board and fixes both the upper and lower cases by soldering, and the lower case is provided with an engaging leg that penetrates the printed wiring board and prevents the lower case from falling off, and is provided in either the upper case or the lower case at a position corresponding to the fixed leg, and has a tip extending from the fixed leg. A protection device for electronic control circuits in which a fixing claw is provided that is inclined at a predetermined angle with respect to the direction, and the fixing claw and the fixing leg are soldered.