JPH1070381A - Securing structure for wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for securing a wiring board to be encased surely without enhancing the dimensional accuracy of the case. SOLUTION: The wiring board securing structure 1 is provided, on the lower case 2b constituting a case 2, with a stopper protrusion 24a comprising a counterbore 26 for mounting a wiring board 3 and a flexible stopper pawl 27. An upper case 2a is provided with a rib 14b for pressing the stopper pawl 27 and when the upper case 2a is applied to the lower case 2b, the stopper pawl 27 is pressed by the (rib 14a) thus securing the wiring board 3 surely and firmly onto the counterbore 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring board fixing structure for fixing a wiring board on which various electronic components are mounted to an electronic device or an electric connection box, and more particularly, to assembling and fixing a wiring board in a special case. And a fixing structure for a wiring board configured to be able to perform the operations collectively.

[0002]

2. Description of the Related Art Automobiles have become increasingly automated and are equipped with various electronic devices for traveling control, electric junction boxes in which fuses, relay switches and the like are assembled. Some electric connection boxes have a case in which a wiring board on which various electronic components are mounted is housed.

An example of a conventional wiring board fixing structure will be described below with reference to FIGS. 6 and 7. FIG. As shown in FIG. 6, the fixing structure of the wiring board is applied to a case 31 assembled in an electric junction box. The case 31 is composed of an upper case 32a and a lower case 32b integrally formed of a synthetic resin, and covers the lower case 32b by covering the upper case 32a with the lower case 32b. Is fixed.

The upper case 32a includes a top plate portion 41, side plate portions 42a to 42d formed around the top plate portion 41,
It has locking claws 43a and 43b formed on the side plate portion 42a, and four pressing ribs 44a to 44d formed downward from the lower surface of the top plate portion 41. The connector hole 45 formed in the top plate portion 41 is for inserting a connector (not shown) provided in the wiring board 33.

[0005] On the other hand, the lower case 42b is formed by integrally molding a synthetic resin into a box shape, and is formed on a bottom plate portion 51, side plate portions 52a to 52d formed around the bottom plate portion 51, and a side plate portion 52a. Locking holes 53a, 53b, locking holes 53c, 53d formed in side plate portion 52c, and bottom plate portion 2
There are provided base portions 54a to 54d formed at four corners of the device. A case 3 is provided outside the side plates 52a and 52b.
Locking portions 55a to 55d for locking and fixing 1 to an electric connection box or the like
Is provided.

Next, a method of fixing the wiring board 33 will be described.
The wiring board 33 is placed on d. Next, the upper case 32a
The pressing ribs 44a to 44d formed on the lower case 32b are inserted into the lower case 32b, and the upper case 32a is lowered as it is, and the locking claws 43a, 43b are locked with the locking holes 53a, 53 as shown in FIG.
b. The locking claws 43a and 43b have elasticity due to slits formed on both sides. Therefore, when locking in the locking holes 53a and 53b, the locking claw 4
3a and 43b get on the side plate portion 52a, temporarily deform, and then fit into the locking holes 53a and 53b so that a click feeling can be obtained.

A locking claw (not shown) is also formed on the side plate 42c of the upper case 32a.
Are locked in locking holes 53c, 53d formed in the side plate portion 52c, but no slit is formed in the locking claw. Therefore, when assembling the upper case 32a to the lower case 32b, the upper case 32a is slightly inclined, and the locking claws on the side plate 42c side are inserted into the locking holes 53c, 53d.
Next, the locking claws 43a and 43b are inserted into the locking holes 53 as described above.
a, 53b.

As described above, the upper case 32a and the lower case 32
In the state where b is integrated, initially, the bases 54a to 54d
The wiring board 33 placed on the top is replaced with four pressing ribs 4.
4a to 44d. Therefore, the wiring board 33 is fixed in the case 31 between the pedestals 54a to 54d and the pressing ribs 44a to 44d.

Next, another example of the fixing structure of the wiring board is shown in FIG.
It will be described based on. As shown in FIG.
Although the upper case 62a and the lower case 62b are provided, the upper case 62a is not formed with any of the above-described pressing ribs 44a to 44d (see FIG. 6). In addition, locking portions 64 are formed at four corners on the bottom plate portion 63 constituting the lower case 62b. The locking portion 64 is provided with a base 64
a and a locking claw 64b. Wiring board 33
When the locking portion 64 is locked to the locking portion 64, the wiring board 33 is bent and pinched between the base portion 64a and the locking claw 64b, and the bending is released, so that the connection between the base portion 64a and the locking claw 64b is released. Locked in between.

On the other hand, the side plate 6 forming the lower case 62b
A locking claw 66 is formed on the upper part of the fifth member 5, and a locking hole 68 is formed on the side plate 67 constituting the upper case 62 a.
Then, after the wiring board 33 is locked to the locking portion 64, the upper case 62a is put on the lower case 62b, and the locking claws 66 are locked in the locking holes 68 to integrate the two. The assembled and fixed case 61 is completed. That is,
In the case 61, the wiring board 33 is connected to the upper case 62a.
Is fixed to the lower case 62b.

[0011]

However, the above-described first example of the fixing structure of the wiring board is not limited to the pedestals 54a to 54d.
And the pressing ribs 44a to 44d sandwich the wiring board 33. However, since both have no elasticity, if there is a dimensional error in the thickness of the wiring board 33, the pressing ribs 44a to 44d and When there is a dimensional error in the portions 54a to 54d, there is a problem that rattling occurs.
Moreover, since the pressing ribs 44a to 44d are formed integrally with the upper case 32a, and the pedestals 54a to 54d are formed integrally with the lower case 32b, a forming error easily occurs, and play is easily generated. As one means for solving this problem, there is an improvement in dimensional accuracy. However, an attempt to improve the dimensional accuracy of the mold leads to an increase in cost.

On the other hand, the above-described wiring board fixing structure of the second example is such that the wiring board 33 is disposed between the base 64a and the locking claw 64b.
Since there is an error in the thickness dimension of the wiring board 33, there is a problem that rattling occurs. Also, if there is an error in the gap between the base 64a and the locking claw 64b, rattling occurs even if the thickness of the wiring board 33 is accurate. And since the locking claw 64b does not have elasticity and cannot elastically press down the wiring board 33, in order to prevent backlash, there is only an improvement in dimensional accuracy as described above, and there is a similar problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fixing structure of a wiring board configured so that the wiring board can be securely fixed to a case or the like without play.

[0014]

The above objects of the present invention can be solved by the wiring board fixing structure described in 1) and 2) below. 1) In a wiring board fixing structure for fixing a wiring board on which various electronic components are mounted to an electronic device or the like, a case including a lower case for housing the wiring board and an upper case for covering and locking the lower case; Formed in the lower case,
A plurality of locking projections each including a pedestal on which the wiring board is mounted and a flexible locking claw that locks the wiring board; and a plurality of locking protrusions formed on the upper case and covering the lower case. And a pressing rib for pressing the locking claw to fix the wiring board between the base and the pedestal. 2) The wiring board according to claim 1, wherein a tapered surface is formed on the pressing rib, and the locking claw is pressed by the tapered surface in conjunction with an action of placing the upper case on the lower case. Fixed structure.

According to the wiring board fixing structure having the above-described structure,
At the four corners of the bottom plate of the box-shaped lower case, locking projections composed of a pedestal and flexible locking claws are formed, and pressing ribs are provided at positions corresponding to the locking projections of the upper case covering the lower case. Is formed. When the lower case is covered with the upper case in a state in which the wiring board is placed on the pedestal and temporarily locked by the locking claw, the pressing rib presses the locking claw by the tapered surface and is placed on the pedestal. The fixed wiring board is fixed to the pedestal without play. Therefore, even if there is a dimensional error in the thickness of the wiring board, or if there is a molding error or the like in the pedestal or the locking claw,
The wiring board can be securely fixed by the pressing of the locking claws, thereby improving the reliability of the electronic device and reducing the production cost.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a wiring substrate fixing structure (hereinafter simply referred to as a fixing structure) to which the present invention is applied will be described in detail with reference to FIGS. FIG.
Is an exploded perspective view showing the configuration of the upper and lower cases to which the fixing structure of the present invention is applied, FIG. 2 is a plan view showing the internal configuration of the lower case,
3 is a cross-sectional view of a main part showing the configuration of the upper and lower cases, FIG. 4 is a cross-sectional view of the main part showing a procedure for fixing the wiring board, and FIG. 5 is a cross-sectional view of the main part showing a fixing operation of the wiring board. In the description of the present embodiment, first, the configuration of the upper and lower cases to which the fixing structure is applied will be described, and then the fixing operation of the wiring board will be described.

As shown in FIG. 1, a fixing structure 1 according to the present embodiment is applied to a case 2 assembled to an electric junction box or the like mounted on an automobile. This case 2
Upper case 2a and lower case 2b integrally formed of synthetic resin
The upper case 2a closes the lower case 2b,
That is, the wiring board 3 assembled in the lower case 2b is fixed by covering. Upper case 2a
The top plate 11, side plate portions 12 a to 12 d formed around the top plate portion 11, locking claws 13 a and 13 b formed on the side plate portion 12 a, And four pressing ribs 14a to 14d formed in the direction of. The connector hole 15 formed in the top plate 11 is
This is for inserting a connector (not shown) provided on the wiring board 3.

On the other hand, the lower case 2b is made of a synthetic resin and is integrally formed into a box shape.
1, side plate portions 22a to 22d, locking holes 23a and 23b formed in the side plate portion 22a, and side plate portion 2
2b and the bottom plate portion 21
Are provided at the four corners of the projections 24a to 24d (see FIG. 2). Locking portions 25a to 25d for fixing the lower case 2b to, for example, an electric connection box or the like are provided outside the side plate portions 22a and 22b.

Next, the pressing rib 1 formed on the upper case 2a
4a to 14d and locking projections 24 formed on the lower case 2b.
a to 24d will be described. Pressing ribs 14a to 14d
Has an action of fixing a wiring board 3 described later without backlash by a cooperative action with the locking projections 24a to 24d. As shown in FIG. 3, each of the pressing ribs 14a to 14d has a vertical outer surface a and a tapered inner surface b. Each of the pressing ribs 14a to 14d has a distal end portion which is in contact with an inner surface of the side plate portion 22a to 22d and a locking projection 24a.
To 24d is formed at a position to be inserted into the gap G formed between them.

Further, as shown in FIG.
24d has an action of locking the wiring board 3, and is formed at four corners on the bottom plate portion 21 constituting the lower case 2b. In the following, the configuration of the locking projections 24a to 24d will be described by taking the locking projection 24a as an example. As shown in FIG. 3, the configuration is such that a flexible locking claw 27 is provided on a base 26. The rear sides of the pedestal 26 and the locking claw 27 are formed on a vertical wall surface, and a gap G is formed between the wall surface and the inner surface of the side plate portion 22a. Locking projections 24a to 24d
Are disposed on the bottom plate 21 such that the locking claws 27 face each other (see FIG. 2).

Next, the fixing operation of the wiring board 3 will be described.
When the wiring board 3 is fixed as shown in FIG. 3, the wiring board 3 is placed on the locking claw 27 and is pushed downward as it is. The locking claw 27 is flexible and has a tapered surface formed on the upper surface thereof.
Is returned to the original shape as shown by the solid line while being placed on the pedestal 26. At this time, the gap G temporarily narrows, but returns to the original gap G again as the shape of the locking claw 27 returns.

In this manner, the four locking projections 24a to 24a.
After temporarily fixing the wiring board 3 to 24d, the upper case 2a is covered as shown in FIG. At this time, the pressing ribs 14a, 1
4b extends along the side plate 22a of the lower case 2b,
4c and 14d are covered along the side plate part 22c of the lower case 2b. Therefore, the pressing ribs 14a to 14d are smoothly pushed into the lower case 2b, and by continuing this pushing, the locking claws 13a to 1d of the upper case 2a are kept.
The 3d tapered surface is applied to the upper ends of the side plates 22a to 22d, and the resistance at the time of pushing is increased. When the locking claw 13b is further pressed in this state, the locking claw 13b bends and deforms outward as indicated by the imaginary line, and the locking claw 13b rides on the upper end of the side plate portion 22a. Then, as shown in FIG. 5, by continuing to push in further, the locking claw 13b is locked in the locking hole 23b, and the upper case 2a and the lower case 2b are integrated.

On the other hand, the thickness of the tip of the pressing rib 14b is
Since it is smaller than the gap G, it is easily inserted into the gap G by pushing the upper case 2a. However, since the inner surface b of the pressing rib 14b is formed as a tapered surface, the pressing rib 1
By pushing the 4b, the locking claw 27 is pressed inward. Such pressing of the locking claws 27 is simultaneously performed on the pressing ribs 14a to 14d and the locking projections 24a to 24d. Therefore, the wiring board 3 is placed on the pedestal portion 26 of each of the locking projections 24a to 24d and is pressed down by the locking claw 27, so that the wiring board 3 is fixed to the lower case 2b without play.

FIG. 5 shows the locking claw 13b and the locking hole 23.
3B, four locking claws 13a to 13d formed on the upper case 2a are actually replaced with four locking holes 23a to 23d formed on the lower case 2b. Respectively. Therefore, the upper case 2a and the lower case 2b are firmly integrated, and the pressing ribs 14a to 14d
Floating is completely prevented. As a result, the locking claw 27 in each of the locking projections 24a to 24d is
The pressing is continued by a to 14d, and the fixing of the wiring board 3 is continuously performed.

As described above, in the wiring board fixing structure 1 of the present embodiment, the operation of temporarily locking the wiring board 3 on the pedestal 26 and then putting the upper case 2a on the lower case 2b. In relation to the locking claws 2 by the pressing ribs 14a to 14d.
7, the wiring board 3 can be fixed without play. That is, the wiring board 3 is provided with the pressing ribs 14a to 14a.
Since the locking claw 27 is fixed by indirect means of pressing the locking claw 4d, the wiring board 3, the pedestal 26, and the locking claw 27 can be securely fixed in the lower case 2b even if there is a dimensional error. .

[0026]

As described above, in the wiring board fixing structure according to the present invention, a case composed of a lower case for accommodating the wiring board, an upper case for covering and locking the lower case, A plurality of locking projections formed of a pedestal for mounting the wiring board and flexible locking claws for locking the wiring board; and a plurality of locking projections formed on the upper case and covering the lower case. Pressing ribs for pressing the pawls to fix the wiring board to the pedestal. In addition, a taper surface is formed on the pressing rib, and the locking claw is pressed by the taper surface in conjunction with the action of placing the upper case on the lower case.

Therefore, in connection with the operation of temporarily locking the wiring board on the pedestal and placing the upper case on the lower case, the pressing rib presses the locking claw and fixes the wiring board in the case without play. be able to. Therefore, the wiring board
Since the fixing ribs are fixed by indirect means of pressing the locking claws by the pressing ribs, even if there are dimensional errors in the wiring board, the pedestal, and the locking claws, they can be securely fixed in the lower case, and the mold It is not necessary to improve the dimensional accuracy such as the above, and the cost can be reduced. In addition, since the wiring board is securely and firmly fixed in the case without play, the reliability of an electronic device or the like to which the fixing structure is applied can be improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a case showing an embodiment of a wiring board fixing structure to which the present invention is applied.

FIG. 2 is a plan view showing a configuration of a lower case in FIG.

FIG. 3 is a sectional view showing a main part of the upper and lower cases in FIG. 1;

FIG. 4 is a cross-sectional view showing an operation when the upper case in FIG. 3 is put on the lower case.

FIG. 5 is a cross-sectional view showing a state in which a locking claw is pressed by a pressing rib in FIG. 4 and a wiring board is fixed.

FIG. 6 is an exploded perspective view of a case showing a first example of a conventional wiring board fixing structure.

7 is a cross-sectional view of a main part showing a fixed state of the wiring board in FIG. 6;

FIG. 8 is a cross-sectional view of a main part showing a second example of a conventional wiring board fixing structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed structure of wiring board 2 Case 2a Upper case 2b Lower case 3 Wiring board 12a, 12b, 12c, 12d Side plate 13a, 13b Locking claw 14a, 14b, 14c, 14d Pressing rib 21 Bottom plate 22a, 22b, 22c, 22d side plate portion 23a, 23b, 23c, 23d locking hole 24a, 24b, 24c, 24d locking projection 26 pedestal 27 locking claw

[Procedure amendment]

[Submission date] March 24, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

On the other hand, the lower case 32b is formed of a synthetic resin integrally formed in a box shape, and is formed on a bottom plate portion 51, side plate portions 52a to 52d formed around the bottom plate portion 51, and a side plate portion 52a. Locking holes 53a, 53b, locking holes 53c, 53d formed in side plate portion 52c, and bottom plate portion 5
There are provided base portions 54a to 54d formed at four corners of the device. A case 3 is provided outside the side plates 52a and 52b.
Locking portions 55a to 55d for locking and fixing 1 to an electric connection box or the like
Is provided.

Claims (2)

[Claims] 1. A wiring board fixing structure for fixing a wiring board on which various electronic components are mounted to an electronic device or the like, comprising: a lower case for housing the wiring board; and an upper case for covering and locking the lower case. A case, a plurality of locking projections formed in the lower case, the base including the pedestal on which the wiring board is mounted, and a flexible locking claw for locking the wiring board; and a plurality of locking projections formed on the upper case. And a pressing rib that presses the locking claw while fixing the lower case to fix the wiring board to the pedestal. 2. A locking taper according to claim 1, wherein a tapered surface is formed on said pressing rib, and said locking claw is pressed by said tapered surface in conjunction with an action of covering said upper case on said lower case. Wiring board fixing structure.