JP2000244153A - Electronic control unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely load a printed board in a case of a simple constitution, without being affected by variations of board thickness, etc. SOLUTION: A plurality of projection parts 12a, 12b are formed alternately at a bottom part 11b of an inner wall surface of a case 11 keeping a space to both sides of a printed board 15. Therefore, even if the printed board 15 is a slightly large in thickness with respect to the prescribed dimensional interval of the projection parts 12a, 12b, it is bent along the protrusions 12a, 12b and fixed surely to a prescribed position. Thereby, a highly reliable electronic control unit can be constituted, without causing built-in defects when the printed board 15 is loaded in the case 11 and without causing damages, etc., in a wiring pattern of the printed board 15, a mounted electronic component, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic control device in which a printed circuit board on which a plurality of electronic components are mounted is housed in a case.

[0002]

2. Description of the Related Art Conventionally, as shown in a partially sectional perspective view of FIG.
Is inserted in the direction along the plane of the board, and two rail-shaped opposed projections 32a and 32b formed on the bottom 31b of the inner wall surface of the case 31 are used to insert the printed circuit board 35 into its edge. 2. Description of the Related Art An electronic control device in which a surface is sandwiched and fixed is known. The printed circuit board 35 is fixed after the end edge surface of the insertion tip is sandwiched and fixed by the projections 32a and 32b, and the opening side of the case 31 is fixed by screws or the like.

[0003]

By the way, in the above-mentioned case, the size of the gap between the projections 32a and 32b for holding the printed board 35 formed on the bottom 31b of the inner wall surface of the case is determined by the printed board 35 used. Is determined by the thickness of the sheet. Therefore, as shown in FIG. 8A, the protrusion 3 formed on the bottom 31b of the inner wall surface of the case.
When the thickness of the printed circuit board 35 is small with respect to the gap size between 2a and 32b, rattling occurs. Therefore, abnormal noise is generated due to vibration or impact applied to the case side, or the wiring pattern (not shown) of the printed circuit board 35 or mounted. There was a problem that electronic parts were damaged.

On the other hand, as shown in FIG. 8 (b), the total thickness of the printed circuit board 35 'is added to its own thickness by, for example, the thickness increase due to the application of the moisture proof agent 36 when the moisture proof treatment is applied. Will be done. This printed circuit board 3
The increase in the thickness due to the application of the moisture-proofing agent 36 to the 5 'is extremely difficult to control the process, and the variation in the total thickness of the finish is large. In addition, when the moisture-proofing treatment is performed and the moisture-proofing agent 36 accumulates on the edge surface of the printed circuit board 35 'and is in a fixed state, the edge surface of the printed circuit board 35' is fixed to the bottom 31b of the inner wall surface of the case. In this case, the protrusions 32a and 32b formed in the above-mentioned parts do not fit in the gap between the protrusions 32a and 32b.

In view of the above, the present invention has been made to solve such a problem, and it is possible to accommodate a printed circuit board in a case having a simple structure without being affected by variations in the thickness of the printed circuit board and securely fix it. The task is to provide possible electronic control devices.

[0006]

According to the electronic control device of the present invention, the plurality of projections formed on the bottom of the inner wall surface of the case are formed at intervals on the front and back surfaces of the printed circuit board. I have. For this reason, in the case of a printed circuit board having a thickness substantially equal to a predetermined dimension interval of the projection formed on the bottom of the inner wall surface of the case, the original flat state is maintained and the printed circuit board is securely fixed at the predetermined position. Further, even if the printed circuit board is thicker than a predetermined dimension interval of the projections formed on the bottom of the inner wall surface of the case, it is curved along the projections and securely fixed at a predetermined position. As a result, when the printed circuit board is inserted in a direction along the plane of the board and accommodated in the case, no assembly failure occurs, and no damage occurs to the wiring pattern of the printed circuit board, the mounted electronic components, and the like. . In other words, the printed circuit board can be securely fixed at a predetermined position in the case with a simple structure without being affected by variations in the thickness of the printed circuit board due to a layer structure or a moisture proof agent. A highly reliable electronic control device can be constructed. In addition, since a common case can be achieved for a plurality of specifications of the electronic control device, the cost can be reduced.

According to the electronic control device of the second aspect, the slit-shaped cut portion formed on the printed board can reduce the deformation area due to the fixing of the printed board by the projection. Therefore, the printed circuit board can be securely fixed at a predetermined position in the case, and an electronic control device having high reliability against vibration and impact can be constructed. In addition, since a common case can be achieved for a plurality of specifications of the electronic control device, the cost can be reduced.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples.

FIG. 1 is a sectional view showing the overall configuration of an electronic control device according to an embodiment of the present invention. FIG. 2 is a partial sectional perspective view showing a fixed state of a printed circuit board in the case of the electronic control device of FIG. In addition,
In FIG. 2, a wiring pattern of a printed circuit board, mounted electronic components, and the like are omitted.

1 and 2, reference numeral 10 denotes an electronic control unit as an electronic control device.
t; hereinafter referred to as “ECU”). The ECU 10 includes, for example, various electronic components 16a and 16b in a case 11 having a bag shape and a substantially rectangular parallelepiped shape made of aluminum alloy die-casting.
And the like are accommodated therein. An opening 11a is formed in the upper end surface of the case 11 of the ECU 10, and a printed circuit board 15 is inserted from the opening 11a side in a direction along the plane of the board. Case 1
A plurality of protrusions 12 are alternately arranged at predetermined intervals on the front and back surfaces of the printed circuit board 15 on the bottom 11b of the inner wall surface of the printed circuit board 15.
a, 12b are formed.

Of the various electronic components 16a and 16b mounted on the printed circuit board 15, the heat-generating electronic component 16a is made of an aluminum plate or the like, and is mounted on a heat sink 17 having good heat radiation by means of screws, adhesive or the like. Closely attached and fixed. The heat sink 17 is fixed to the printed circuit board 15 by screws. An external connector 18 is soldered and fixed to the printed circuit board 15.

The printed circuit board 15 is the case 1 of the ECU 10.
Projection portions 12a, 1 formed on bottom 11b of inner wall surface
2b, and the heat sink 17 is screwed through a through hole (not shown) formed in the case 11 of the ECU 10.
It is fixed at. As described above, when the printed board 15 is inserted into the case 11 of the ECU 10 in a direction along the plane of the board, the external connector 18 is positioned on the opening 11a side of the case 11, and the external connector 18
When the case lid 19 is fixed with screws or the like so as to cover the opening 11a side of the case 11 around the ECU 10, the assembly of the ECU 10 is completed.

Next, the operation of this embodiment will be described with reference to FIG.
This will be described with reference to FIG. 3 showing a cross section taken along line -A.

As described above, the case 11 of the ECU 10
When the printed circuit board 15 is accommodated in the assembled state, the edge surface of the printed circuit board 15 on the insertion front end side has a plurality of protrusions 12 a, 1 formed on the bottom 11 b of the inner wall surface of the case 11.
The front and back surfaces are sandwiched and fixed to 2b. here,
The dimension interval between the projections 12a and 12b formed on the bottom 11b of the inner wall surface of the case 11 of the ECU 10 is set to the minimum thickness in consideration of the dimensional tolerance of the printed board 15 used in design.

As shown in FIG. 3A, a projection 12 formed on the bottom 11b of the inner wall surface of the case 11 of the ECU 10 is provided.
In a state where the thickness of the printed circuit board 15 matches the dimensional interval between the printed circuit boards 15a and 12b, the printed circuit board 15 maintains its original flat state, and the front and back surfaces thereof have the projections 12a and 12b.
It is sandwiched between and fixed securely without rattling.

Further, as shown in FIG.
The printed circuit board 15 ′ has a large thickness due to a dimensional tolerance, a difference in a layer configuration, or a moisture-proof agent applied to a dimensional interval between the protrusions 12 a and 12 b formed on the bottom 11 b of the inner wall surface of the case 11. In the above, the printed circuit board 15 'side is curved along the projections 12a and 12b, and its front and back surfaces are sandwiched between the projections 12a and 12b, and are securely fixed without rattling. At this time, the maximum thickness of the printed board 15 ′ that can be used is the bottom 11 b of the inner wall surface of the case 11.
The wiring patterns and the mounted electronic components are defined in advance so as not to cause damage to the wiring patterns and the mounted electronic components due to the curvature of the projections 12a and 12b formed on the substrate.

The projections 12a and 12b formed on the bottom 11b of the inner wall surface of the case 11 are formed with inclined surfaces such as chamfered shapes on the front end sides of the printed circuit board 15 (15 ') on the clamping side. Then, the projections 12a, 12b
The printed circuit board 15 (15 ') can be easily inserted therebetween, so that workability can be improved.

Next, conditions for mounting the electronic components 16b and the like on the printed circuit board 15 (15 ') will be described with reference to FIG. Here, FIG. 4 is a partial sectional perspective view corresponding to FIG.

In FIG. 4, when the printed circuit board 15 (15 ') is sandwiched and fixed by using the projections 12a and 12b formed on the bottom 11b of the inner wall surface of the case 11, the printed circuit board 15 (15 It is assumed that the mounted electronic component 16b and the like may be damaged by external stress such as bending to '). Therefore, the printed circuit board 1
The printed circuit board 15 (1 ') shown by oblique lines in FIG.
5 ') Electronic component 16b avoiding mounting prohibited area P1 on the surface
Implementing such as is an essential requirement in design.

As described above, the ECU 10 as the electronic control device of the present embodiment includes a printed circuit board 15 (15 ') on which a plurality of electronic components 16a, 16b and the like are mounted and a printed circuit board 15 (15'). 11, which has a bag structure for accommodating the printed circuit board 15 (15 ') so as to be inserted in a direction along the bottom, and a bottom 11b of the inner wall surface of the case 11
And a plurality of protrusions 12a and 12b formed alternately at predetermined intervals on the front and back surfaces of the printed board 15 (15 ') so as to sandwich the printed board 15 (15').

That is, the bottom 11b of the inner wall surface of the case 11
A plurality of projections 12a and 12b
It is formed alternately with an interval on the front and back surfaces of (15 '). For this reason, the bottom 11b of the inner wall surface of the case 11
In the printed circuit board 15 having a thickness substantially equal to the predetermined distance between the projections 12a and 12b formed on the printed circuit board, the original flat state is maintained and the printed circuit board 15 is securely fixed at the predetermined position. Also, a projection 12 formed on the bottom 11b of the inner wall surface of the case 11
Even if the printed circuit board 15 'is thicker than the predetermined dimensional interval between a and 12b, the printed circuit board 15' is curved along the projections 12a and 12b and is securely fixed at a predetermined position. Thus, when the printed circuit board 15 (15 ') is inserted in the direction along the plane of the board and accommodated in the case 11, no assembly failure occurs, and the wiring pattern (not shown) of the printed circuit board 15 (15') Also, there is no possibility that the mounted electronic components 16a, 16b and the like are damaged. That is, the printed circuit board 15 (1
The printed circuit board 15 (1) has a simple configuration without being affected by the layer configuration of 5 ′) or the thickness variation due to the moisture proof agent or the like.
5 ′) can be securely fixed to a predetermined position in the case 11, and the ECU 10 having high reliability against vibration and impact can be constructed. Further, since the case 11 can be shared for a plurality of specifications of the ECU 10, the cost can be reduced.

Next, a modification of the electronic control device according to one embodiment of the present invention will be described with reference to FIG. In the drawings, the same reference numerals and symbols are given to components having the same configuration or corresponding portions as those in the above-described embodiment, and detailed description thereof will be omitted. In FIG. 5, the wiring pattern of the printed circuit board, mounted electronic components, and the like are omitted. Further, the overall configuration of the electronic control device of this modification is the same as the cross-sectional view of FIG. 1 in the above-described embodiment, and a detailed description thereof will be omitted.

As shown in FIG. 5, similar to the above embodiment,
Protrusions 12a, 1
2b is formed. And the printed circuit board 25
An edge surface on the bottom 11b side of the inner wall surface of the accommodated case 11 is sandwiched and fixed by the protrusions 12a and 12b. When the printed board 25 of this modification is sandwiched and fixed by the plurality of protrusions 12a, 12b, the printed board 2 is located at an intermediate position between the adjacent protrusions 12a, 12b.
5, a slit-like cut portion 25a is formed on the edge surface.

For this reason, as shown in FIG. 3B, a projection 12 formed on the bottom 11b of the inner wall surface of the case 11 is formed.
a, 12b with respect to the predetermined dimensional interval.
Even when the thickness is large, the curved portion of the printed board 25 can be accommodated within the cut size of the cut portion 25a. Thereby, similar to the above-described embodiment,
When the printed circuit board 25 is accommodated in the case 11, no assembly failure occurs, and no damage occurs to the wiring pattern (not shown) of the printed circuit board 25, the mounted electronic components 16a, 16b, and the like. That is, the printed circuit board 25 is housed in the case 11 with a simple structure without being influenced by the layer structure of the printed circuit board 25 or the thickness variation due to the moisture proof agent,
The ECU 10 can be reliably fixed at a predetermined position, and a highly reliable ECU 10 against vibration and impact can be constructed.
Further, since the case 11 can be shared for a plurality of specifications of the ECU 10, the cost can be reduced.

Next, the conditions for mounting the electronic components 16b and the like on the surface of the printed circuit board 25 will be described with reference to FIG.
Here, FIG. 6 is a partial sectional view corresponding to FIG.

In FIG. 6, when the printed circuit board 25 is pinched and fixed by using the projections 12a and 12b formed on the bottom 11b of the inner wall surface of the case 11, external stress such as bending on the printed circuit board 25 is applied. It is assumed that the electronic component 16b and the like mounted thereon are damaged. In this modification, the adjacent protrusions 12a, 12a
b, a slit-shaped notch 25a is formed in the edge surface of the printed circuit board 25 at an intermediate position of the printed circuit board 25.
When the protrusion 5 is sandwiched and fixed by the plurality of protrusions 12a and 12b, the portion affected by external stress such as the curvature of the printed circuit board 25 is within the cutout dimension of the cutout 25a, that is, hatched in FIG. Can be accommodated in the mounting prohibited area P2 shown in FIG. That is, the mounting prohibited area P2 of the printed board 25 is
The printed board 15 (1) shown in FIG.
5 ') It can be set narrower than the mounting prohibited area P1 on the surface. Therefore, it is possible to obtain a larger mounting area for the electronic components 16b and the like on the printed board 25 than the printed board 15 (15 ').

As described above, the printed circuit board 25 of the ECU 10 as the electronic control device according to the present modification has the slit-shaped cut portion 25a formed on the edge surface at the intermediate position between the adjacent protrusions 12a and 12b. It is. In other words, the slit-shaped cut portion 25a formed on the printed board 25 can reduce the deformation area associated with the fixing of the printed board 25 by the projections 12a and 12b.
Therefore, the printed circuit board 25 can be securely fixed at a predetermined position in the case 11, and the ECU 10 having high reliability against vibration and impact can be constructed. Also, E
Since the case 11 can be shared for a plurality of specifications of the CU 10, the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an overall configuration of an electronic control device according to an example of an embodiment of the present invention.

FIG. 2 is a partial sectional perspective view showing a fixed state of a printed circuit board in a case of the electronic control device of FIG. 1;

FIG. 3 is a cross-sectional view taken along line AA of FIG.

FIG. 4 is a partial cross-sectional perspective view showing a mounting prohibited area on a printed circuit board of the electronic control device according to one example of the embodiment of the present invention.

FIG. 5 is a partial cross-sectional view showing a modified example of a printed circuit board used in an electronic control device according to one example of an embodiment of the present invention.

FIG. 6 is a partial cross-sectional view showing a mounting prohibited area in a modified example of a printed circuit board of an electronic control device according to one example of an embodiment of the present invention.

FIG. 7 is a partial cross-sectional perspective view showing a fixed state of a printed circuit board and a projection of a case in a conventional electronic control device.

FIG. 8 is a partial cross-sectional view showing a fixed state of a printed circuit board and a projection of a case in a conventional electronic control device.

[Explanation of symbols]

 Reference Signs List 10 ECU (Electronic Control Equipment) 11 Case 11b Bottom part (of inner wall surface) 12a, 12b Projection part 15, 25 Printed circuit board 25a Cut part

Claims (2)

[Claims] 1. A printed circuit board on which a plurality of electronic components are mounted, a case having a bag structure for accommodating the printed circuit board such that the printed circuit board is inserted in a direction along a plane of the printed circuit board, and an inner wall surface of the case A plurality of protrusions formed alternately at predetermined intervals on the front and back surfaces of the printed circuit board so as to sandwich the printed circuit board at the bottom of the electronic control apparatus. 2. The electronic control device according to claim 1, wherein the printed circuit board has a slit-shaped notch formed in an edge surface at an intermediate position between the adjacent protrusions.