JPH09102680A - Frame for electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic mounting step easily for mounting and fixing a plastic cover on a base, by guiding an edge of the cover with a fitting means that is elastically deformed and fitted to the base in a given direction, and fitting the fitting means to a given position of the base. SOLUTION: When a cover 16 is mounted on a base 14, a flange 38 formed in a body with an edge 30a of a wall 30, an edge 32a of a wall 32, and an edge 34a of a wall 34 of the cover 16 is fitted to an outer face of a supporting member 22 to guide the cover 16 to a given mounting position. After the cover 16 is mounted on the given position of the base 14, the flange 38 is fitted to an outer face of the supporting member 22 to prevent mechanical dislocation, in which the cover 16 is moving off the supporting member 22. In addition, edge parts 32b and 34b of walls 32 and 34 have two projected parts 40. These projected parts 40 are fitted to the mounting part 24 and function as a guide member for guiding the edge parts 32b and 24b to the given mounting position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device, and more particularly to a housing for an electronic device including a metal base for supporting the electronic component and a plastic cover attached to the base for covering the electronic component.

[0002]

2. Description of the Related Art In an electronic device such as an electric motor controller, a printed circuit board on which electronic components are mounted is supported by a metal base, and a plastic bag-like cover is attached to the base so as to cover the printed circuit board. A case structure is known. Generally, in a metal base, a large number of heat radiation fins are provided on the surface of the portion supporting the printed circuit board opposite to the printed circuit board in order to promote the dissipation of heat transmitted from the electronic components and the printed circuit board. Further, the plastic cover is effective for protecting the printed circuit board and the electronic components from damages caused by adhesion or collision of foreign matter and reducing the weight of the electronic device.

Conventionally, in order to attach a plastic cover to such a metal base, a flange is provided at an opening edge portion of the cover which comes into contact with the base, and a through hole formed in the flange is provided with a bolt at a corresponding position of the base. There is a method in which the bolt is screwed into the screw hole, or a bolt that is inserted into the through hole provided in the flange of the cover is fixed to the base side and a nut is screwed into the bolt end that passes through the flange. It was being appreciated.

[0004]

In recent years, the process of assembling electronic equipment tends to be automated by using an automatic machine such as a robot. However, in the conventional method of fixing the cover to the base by using the bolts and nuts when assembling the electronic device housing, the base and the cover are supported in a predetermined relative positional relationship, the two are brought close to each other, and Since it has to be screwed on, complicated control is required for a plurality of operating arms when an automatic machine is used, and automatic assembly tends to be difficult.

Further, by forming a flange on the opening edge of the cover, there has been a problem that miniaturization of electronic equipment is hindered. Furthermore, the plastic cover is formed with a thickness of about several mm to reduce weight and external dimensions, so it can be bent relatively easily to change the shape of the opening, and when mounting the cover on the base, bolts and bolt penetrations It may be difficult to align the holes. Such bending of the cover increases the surface area of the base due to the necessity of providing the heat dissipation fins on the metal base, or the base has a multifaceted structure,
As a result, the opening of the cover is enlarged, and it becomes particularly remarkable in the configuration in which the support for the cover wall adjacent to the opening is weakened.

Therefore, an object of the present invention is to provide a housing for an electronic device, which can easily automate the process of attaching and fixing the plastic cover to the metal base and which has a novel fixing structure which contributes to downsizing of the electronic device. To do.

[0007]

In order to achieve the above object, the present invention provides a metal base for supporting electronic parts,
In a housing of an electronic device, which is attached to a base to cover an electronic component, and has a plastic cover having an opening that is substantially closed by the base, elastically deforms when the cover is attached to the base to form a base. Engaging means integrally provided on the cover edge defining the opening to engage and thereby secure the cover to the base, and guide the cover edge in a predetermined direction when attaching the cover to the base. Thus, there is provided a housing for an electronic device, which is provided with a guide means for engaging the engaging means with a predetermined position of the base.

In assembling this housing, when the base and the cover are moved relative to each other while guiding the edge of the cover in a predetermined direction by the guiding means, the engaging means provided on the cover elastically moves with the relative movement. It deforms and engages at a predetermined position on the base. Therefore, the cover is fixedly attached to the predetermined position of the base only by linearly moving the base and the cover linearly in the predetermined direction.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on preferred embodiments with reference to the accompanying drawings. In the drawings, the same or similar components are denoted by common reference numerals. Referring to the drawings, FIG. 1 shows an electronic device 12 including a housing 10 according to an embodiment of the present invention. Case 1
0 includes a metal base 14 that supports electronic components, and a plastic cover 16 that is attached to the base 14 and covers the electronic components. In the illustrated embodiment, the base 14 is a substantially rectangular flat plate-shaped support portion 22 that supports two printed circuit boards 20 on which a large number of electronic components 18 are mounted, and is substantially orthogonal to the support portion 22 from one end of the support portion 22. And a mounting portion 24 having a substantially rectangular flat plate shape that is extended and is used for mounting the electronic device 12 to an external supporting body. The printed circuit board 20 and the support portion 22 respectively include a pair of edge portions 20 a and edge portions 22 a that linearly extend in a direction substantially orthogonal to the mounting portion 24.

As shown in FIGS. 1 and 2, a plurality of supporting portions 22 of the base 14 (for example, 4
The inner surface 22b is formed by projecting the individual columns 26, and the outer surface 22c is formed by projecting a plurality of heat radiation fins 28 in the direction opposite to the columns 26 on the back side of the inner surface 22b. The pillars 26 hold the two printed circuit boards 20 in parallel with each other and substantially in parallel to the support portion 22 with a predetermined gap therebetween, and support the printed circuit boards 20 by an unillustrated screw structure on the inner surface 22 of the support portion 22.
Fix on side b. The support portion 22, the mounting portion 24, and the heat radiation fin 28 of the base 14 can be integrally formed by casting from aluminum, for example.

As shown in FIGS. 1 and 3, the cover 16
Has four substantially rectangular flat plate-shaped walls 30, 32, 34, 36 that are substantially orthogonal to each other and integrally connected at each edge.
When the cover 16 is attached to the base 14 at a predetermined position,
The wall 30 is provided between the mounting portion 24 and the two printed circuit boards 20.
Is disposed substantially parallel to the mounting portion 24 with the interposition of, and the wall 32 and the wall 34 are disposed substantially orthogonal to the support portion 22 and the mounting portion 24 with the two printed circuit boards 20 interposed therebetween.
The wall 36 is provided between the support 22 and the two printed circuit boards 20.
And is disposed substantially parallel to the supporting portion 22 with the intervening.

When the cover 16 is attached to the base 14 at a predetermined position, the housing 10 has a substantially rectangular parallelepiped outer shape, and the two printed circuit boards 20 and the electronic components 18 mounted on them are
It is accommodated in the space surrounded by the support portion 22 and the attachment portion 24 of the base 14 and the walls 30, 32, 34, 36 of the cover 16. At this time, the cover 16 is attached to the wall 3
Edge 30a on the side away from the wall 36 of 0, wall 36 of the wall 32
The edge 32a on the side away from the wall 32 and the edge 32b on the side away from the wall 30 and the edge 3 on the side away from the wall 36 of the wall 34.
4a and the edge defined by the edge 34b on the side remote from the wall 30 is defined by the support 22 and mounting 24 of the base 14.
Substantially closed by. It should be noted that a desired wall of the cover 16 can be provided with a large number of through holes for heat dissipation (FIG. 3 shows the holes 37 provided in the wall 34).

As shown in FIGS. 1 and 4, the edge 30a of the wall 30 of the cover 16, the edge 32a of the wall 32, and the wall 34.
It is preferable that a flange 38 is integrally formed on the edge portion 34a of each of the walls 30, 32, 34 so as to extend in a direction substantially orthogonal to and approaching each other. The flange 38 is used when the cover 16 is attached to the base 14 as described later.
The outer surface 22c of the support portion 22 is engaged with the outer surface 22c of the support portion 22 after the cover 16 is attached to the predetermined position of the base 14. The displacement of the cover 16 in the direction away from is mechanically prevented. In this case, the flange 38 has a size and a shape that do not interfere with the radiation fin 28 provided on the support portion 22 of the base 14.

As shown in FIGS. 1 and 3, two protrusions 40 are respectively provided on the edges 32b and 34b of the walls 32 and 34 of the cover 16 so as to project substantially parallel to the walls 32 and 34, respectively. . The protrusion 40 has a shape in which the diameter is gradually reduced from the base end adjacent to the walls 32 and 34 to the free end. As will be described later, the protrusion 40 is provided when the cover 16 is attached to the base 14.
It acts as a guide unit that engages with the mounting portion 24 and guides the cover edges 32b and 34b to predetermined mounting positions.

Further, each of the walls 32 and 34 is provided with two slits 42 linearly extending from the respective edge portions 32b and 34b toward the wall 30 over a predetermined distance. Part 44 sandwiched between the slits 42 of each wall 32, 34
Has a free end 44a slightly protruding outward from each edge 32b, 34b, and a hook 46 (see FIG. 5B) extending in a direction away from each other is formed at the free end 44a. The slit 42 is dimensioned to allow each portion 44 to resiliently flex with respect to each wall 32, 34. The hook 46 has a hooking surface 46a that extends substantially orthogonal to the inner surfaces 32c and 34c of the walls 32 and 34 that face each other.
And a sliding surface 46 extending obliquely from the tip of the hooking surface 46a.
b and (see FIG. 5B). As will be described later, when the cover 16 is attached to the base 14, the portion 44 and the hook 46 act as engagement means that snap-engage with the attachment portion 24 by elastic deformation and fix the cover 16 to the base 14.

Preferably the inner surface 32 of each wall 32, 34
c, 34c, each edge 32b, 3 adjacent to each protrusion 40.
Two ridges 48 are provided so as to extend linearly from 4b to the wall 30 substantially parallel to the wall 36. As will be described later, when the cover 16 is attached to the base 14,
The two printed circuit boards 20 are engaged with each other to assist the guiding action of the protrusion 40.

The cover 16 can be integrally formed from a plastic material such as ABS resin by injection molding. At this time, for example, when the projection 40 provided on each of the walls 32 and 34 has a diameter larger than the wall thickness, the cover 16 is removed from the mold after molding.
Inner surface 3 of each wall 32, 34 to enable removal of the
2c and 34c have projections 40 at positions aligned with the projections 40.
Inevitably, a ridge 48 having a protrusion dimension corresponding to the diameter of the ridge is formed. Of course, whether the diameter of the protrusion 40 is equal to the wall thickness,
If it is smaller, the protrusion 4 is irrespective of the position of the protrusion 40.
8 can be formed.

As shown in FIGS. 1 and 5, the protrusions 4 of the walls 32 and 34 of the cover 16 are attached to the mounting portion 24 of the base 14.
Four through holes 50 for receiving each protrusion 40 are provided at each position corresponding to 0, and each free end 44a is received at each position corresponding to the free end 44a of the portion 44 of each wall 32, 2. Two stepped through holes 52 are provided. Each through hole 50,
52 receives the protrusions 40 and the free ends 44a when the cover 16 is in the original shape without deformation, and the cover 1
6 is arranged at a position where it can be accurately held at a predetermined mounting position with respect to the base 14. Preferably, the through hole 50 is the protrusion 4
The inner diameter is slightly larger than the maximum outer diameter of 0, and the mounting portion 24
The peripheral edge of the opening on the inner surface 24a side is chamfered. Further, the stepped through hole 52 has a shoulder surface 52a which is narrowed in a stepwise manner on the inner surface 24a side of the mounting portion 24 and which is engageable with the hooking surface 46a of the hook 46 provided at the free end 44a. Instead of these through holes 50 and 52, blind holes having the same shape can be used.

As shown in FIG. 4, the supporting portion 2 of the base 14
The distance between the two edge portions 22a of the two and the distance between the edge portions 20a of each printed circuit board 20 supported by the support portion 22 are the inner surface dimension L between the wall 32 and the wall 34 of the wall 36 of the cover 16. Is almost equal to. Furthermore, both printed circuit boards 2
The distance between the surfaces 20b which are separated from each other is 0.
The distance D between the two ridges 48 provided on each of the walls 32 and 34 is substantially equal.

The casing 10 of the electronic device 12 having the above structure
According to this, the assembly process of the base 14 and the cover 16 by an automatic machine becomes extremely easy. First, as shown in FIG. 1, the base 14 supporting the printed circuit boards 20 is placed stationary, and the mounting portions 24 and the walls 30 are provided on the side of each printed circuit board 20.
The cover 16 is arranged so that and are opposed to each other in parallel. Next, the cover 16 is moved toward the mounting portion 24 of the base 14 in the direction of the arrow A in the drawing, and the inner surfaces 32c and 34c of the walls 32 and 34 of the cover 16 are moved to the edges 2 of the support portion 22 of the base 14.
2a and both edges 20a of each printed circuit board 20 are engaged, and the inner surface of the flange 38 of the cover 16 is engaged with the outer surface 22c of the support portion 22. At this time, as shown in FIG. 4, the surface 20 b adjacent to both edges 20 a of each printed circuit board 20 engages with the two ridges 48 of each wall 32, 34 of the cover 16. When the cover 16 is further moved toward the mounting portion 24 of the base 14 in this state, the both edge portions 22a of the support portion 22 and the both edge portions 20a of each printed circuit board 20 are moved to the inner surfaces 32c of the respective walls 32, 34 of the cover 16. It slides on 34c, and the edges 32b and 34b of the cover 16 are guided to predetermined attachment positions by the action of the flange 38 and the protrusions 48.

The edge 32 of each wall 32, 34 of the cover 16
When b and 34b come close to the inner surface 24a of the mounting portion 24 of the base 14, each protrusion 40 is inserted into each through hole 50 of the mounting portion 24, and the free end 44a of each portion 44 is connected to each stepped through hole 52.
Is inserted into. At this time, the tapered shape of the protrusion 40 and the chamfering of the opening of the through hole 50 facilitate the insertion of the protrusion 40 into the through hole 50, and the misalignment between the protrusion 40 and the through hole 50 as the protrusion 40 progresses. Modified (Figure 5)
(A), (c)). It should be noted that such misalignment often occurs easily in the cover 16 having a large opening as in the illustrated embodiment, because each wall bends due to the material characteristics of the cover 16. Is.
In the case 10, when the cover 10 is attached to the base 14,
By engaging both edges 32a of the support portion 22 and both edges 20a of each printed circuit board 20 with both walls 32 and 34 of 6, the bending of each wall is eliminated to some extent, and the through hole 50 is further formed.
By inserting the protrusion 40, it is almost completely eliminated.

Simultaneously with the insertion of the protrusion 40, the free end 44a of each portion 44 is slidably in contact with the opening peripheral edge of the stepped through hole 52 on the inner surface 24a side of the mounting portion so that the sliding surface 46b of the hook 46 slidably contacts the free end 44a. As each part 44 progresses, the inner wall surface 32c, 3
It is inserted into the stepped through hole 52 while elastically bending toward the 4c side. When the free end 44a further advances and the hook 46 gets over the peripheral edge of the opening, each part 44 elastically restores and the hook 4
The latching surface 46a of 6 snap-engages with the shoulder surface 52a of the stepped through hole 52 (FIGS. 5A and 5B). At this time, the walls 32 and 34 of the cover 16 are arranged at predetermined mounting positions with respect to the base 14 by the action of the projection 40, so that the hooking surface 46a of the hook 46 is the shoulder surface 52a of the stepped through hole 52.
Accurately engages with and secures the fixing action.

As described above, according to the housing 10, the cover 16 is guided to the predetermined mounting position only by linearly moving the cover 16 in the predetermined one direction with respect to the stationary base 14. A cover 16 is fixedly attached to the base 14. Therefore, the number of assembling steps of the casing 10 is reduced, the number of automatic machines can be reduced, and the control thereof is facilitated, so that the automatic assembling of the casing 10 is promoted. Further, since separate parts such as bolts and nuts are not required to attach the cover 16 to the base 14, the number of parts can be reduced and inventory management of parts can be simplified.
Further, since the portion for forming the hole for receiving the bolt can be eliminated from the base and the cover, it contributes to downsizing of the electronic device.

The housing of the electronic device according to the present invention can have various configurations other than the above-mentioned embodiment. For example, as a guide means, as shown in FIG. 6A, a protrusion 54 is provided in the attachment portion 24 of the base 14 instead of the through hole 50, and the protrusions 40 of the walls 32 and 34 of the cover 16 are eliminated to remove the edge. Part 3
2b and 34b themselves may be engaged with the protrusion 54. Further, as shown in FIG. 6B, each wall 32, 34 of the cover 16 is
In addition, one ridge 48 is formed so that the edge portion 22a of the support portion 22 of the base 14 is sandwiched between the flange 38 and the ridge 48.
Can be arranged so that the cover 16 can be guided regardless of the printed circuit board. The hook 46 forming the engaging means may be provided on the free end 44a of the portion 44 so as to project in the direction opposite to the illustrated embodiment. In this case, as shown in FIG. 6C, instead of the stepped through hole 52, the edge of the attachment portion 24 is cut out in the base 14 to form a stepped edge portion 56 with which the hook 46 can be engaged. May be.

The housing of the electronic device according to the present invention is, as in the above-described embodiment, given two adjacent surfaces of the rectangular parallelepiped (in the above-described embodiment, the support portion 22 provided with the radiation fins 28 and the attachment to the external body). In the case where the base forming part 24) and the cover forming the other four surfaces are combined, even if the plastic cover is deformed due to the relatively large opening, the cover is automatically attached as described above. Is particularly advantageous as it can be possible. In this case, the wall 36 of the illustrated cover 16 may be omitted if desired. However, it goes without saying that the engaging means and the guiding means can be provided in the same manner even for a housing formed of a combination of a base forming one surface of a rectangular parallelepiped and a cover forming the other five surfaces. . Further, it can be applied to a case having an outer shape other than a rectangular parallelepiped, such as a cylinder, a cone, or a sphere.

[0026]

As is apparent from the above description, according to the present invention, the cover edge portion provided with the engaging means for elastically deforming and engaging the base when the plastic cover is attached to the metal base. Is guided in a predetermined direction by the guide means,
Since the engaging means is configured to engage with the predetermined position of the base, the cover can be fixedly attached to the predetermined position of the base only by linearly moving the base and the cover linearly in the predetermined direction. . Therefore, according to the present invention, it is possible to easily automate the process of attaching and fixing the cover to the base, and to provide the housing of the electronic device that contributes to downsizing of the electronic device.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an electronic device including a housing according to an exemplary embodiment of the present invention.

FIG. 2 is a plan view showing the base of the housing of FIG. 1 in the direction of arrow II with electronic components omitted.

FIG. 3 is a cross-sectional view showing the cover of the housing of FIG. 1 along the line III-III.

4 is a cross-sectional view taken along line IV-IV with the cover of the housing of FIG. 1 attached to a base and omitting electronic components.

5 is a view showing a mounting portion between the cover and the base of the housing of FIG. 1, and is a partially enlarged cross-sectional view taken along line (a) line Va-Va;
(B) Partial enlarged sectional view along line Vb-Vb, and (c) line
It is a partial expanded sectional view along Vc-Vc.

6A and 6B are views showing a modified example of the housing of the present invention, in which FIG. 6A is a partially enlarged perspective view of a base, FIG. 6B is a partially enlarged sectional view of a cover, a base, and a printed circuit board; and FIG. It is an expansion perspective view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Housing 14 ... Base 16 ... Cover 20 ... Printed circuit board 22 ... Supporting part 24 ... Attachment part 30, 32, 34, 36 ... Wall 38 ... Flange 40 ... Protrusion 42 ... Slit 44 ... Part 46 ... Hook 48 ... Projection strip 50 ... through hole 53 ... stepped through hole

Claims (1)

[Claims] 1. A metal base for supporting electronic components,
In a housing of an electronic device, which is attached to a base to cover an electronic component and has a plastic cover having an opening that is substantially closed by the base, elastically deforms when the cover is attached to the base. Engagement means integrally provided on the cover edge defining the opening to engage and thereby secure the cover to the base, and guide the cover edge in a predetermined direction when attaching the cover to the base. Then, a guide means for engaging the engaging means with a predetermined position of the base, and a housing of the electronic device.