JPH0621666A - Enclosed housing structure for electronic equipment - Google Patents

Abstract

PURPOSE:To acquire a housing, while reducing the assembling manpower, whose hermetic seal is assured by containing a printed board in a case which is closed by making opening surfaces of plastic boxes mutually and by fixing both half bodies by at least one screw which passes therethrough. CONSTITUTION:A printed board 3 is contained in a hermetically sealed space which consists of a first half body 1 consisting of a rectangular ceiling wall and an outer peripheral wall and a second half body 2 which consists of a rectangular ceiling wall and an outer peripheral wall of a specified height of a peripheral edge. A female stud 6 having a relief hole 6a at a specified height is projectingly provided to four corners of an inner surface of the ceiling wall of the first half body 1, and a male stud 4 having a wear washer 4a of a large diameter of a specified height, a pin part 4b of a small diameter and a cut-out 4c is projectingly provided to a position corresponding to the female stud 6 in an inner surface of a ceiling wall of the second half body 2. An end of the pin part 4b is formed to a rising part. Therefore, during fitting, mutual positions are locked to prevent a substrate 3 from returning to its original state and removing after the pin part 4b passes through an attaching hole 9, thereby forming a cage body with a closed space.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetically sealed enclosure for accommodating electronic equipment such as digital line terminators.

[0002]

2. Description of the Related Art Since such a device is often installed in an environment where it is exposed to natural conditions such as under the eaves of a house, it is required to be waterproof and dustproof. As shown in FIG. 9, the conventional housing structure is composed of a durable upper case 21 and a lower case 22 made of ABS resin. The upper case 21 is
A rib 2 that projects downward over substantially the entire circumference of the mating surface formed by the tip surface of the outer peripheral wall having a predetermined thickness.
3, the lower case 22 is provided with a groove 24 having a U-shaped cross section along the entire circumference on the mating surface also formed by the tip end surface of the outer peripheral wall. And the upper and lower cases 21,
When 22 are combined, the ribs 23 of the upper case 21 are configured to fit inside the outer peripheral wall of the lower case 22.

In order to accommodate the printed circuit board 25 constituting the electronic device in the upper and lower cases 21, 22, the printed circuit board 25 is first mounted on the tip surfaces of a plurality of studs 26 projecting from the bottom surface of the lower case 22. The stud 26 and the screw 28 from above through a mounting hole 27 provided in the printed circuit board 25 corresponding to the stud 26.
The printed circuit board 25 is fixed in the lower case 22 by being screwed into the female screw 30 at the tip of the. Next, in the groove 24 of the lower case 22, a rubber packing 29 having a shape that fits the groove 24 is fitted. Finally, the upper case 21 is fitted and positioned in the lower case 22 as described above, a plurality of screws 31 are inserted from the bottom surface side of the lower case 22 through the through holes 30, and the tips thereof correspond to the upper case 21. The both are fixed by being screwed into the screw hole 32. by this,
A waterproof and dustproof closed housing is completed.

Further, as input / output terminals for the printed circuit board 25 housed in the case, the L-shaped connection terminals 33 are integrated by insert molding when the lower case 22 is molded, and as shown in FIG. The lead 33a provided at the projecting end inside the case is inserted into the through hole 34 of the printed board 25 and electrically connected to the printed board by soldering.

[0005]

In such a conventional housing structure, a large number of screws are required to secure the printed circuit board and the hermeticity of the case, and the rubber packing is interposed. , The following problems exist. 1) The number of parts is large and inventory management becomes troublesome.

2) Torque management is required for screw tightening work, resulting in high assembly cost. 3) Since a flexible rubber packing is incorporated, it is difficult to handle by a robot. 4) The screws for fixing the cases to each other are inserted from the bottom side of the housing to conceal the screw head, and the tightening operation is performed, but this work needs to be performed by reversing the housing,
The work process increases.

5) The connection terminals are integrated with the case by insert molding, but the positioning accuracy thereof is required to be high, and accordingly, the mold and parts are expensive. 6) Insert molding requires a lot of man-hours. 7) Temperature control of the insert mold is difficult, and defects such as warpage and sink marks are likely to occur. In order to prevent this, it is necessary to perform gentle temperature control, resulting in a longer molding time.

The present invention solves the above-mentioned problems of the prior art and, despite the simple structure requiring a small number of assembling steps, has a high dimensional accuracy and a conventional hermetically sealed enclosure for electronic equipment. It is intended to provide a structure.

[0009]

The first and second plastic box molds which are made by injection molding and are surrounded by a top wall and an outer peripheral wall and have one of upper and lower surfaces open.
Forming a sealed case body with the open surfaces of the halves facing each other, and housing the printed circuit board in its internal space,
A sealed housing structure for an electronic device, which is configured to be positioned and fixed on an appropriate mounting surface by at least one screw penetrating both halves, the side surface of a top wall of the first half. The outer surface of the outer peripheral wall has a size that can be fitted to the inner surface of the outer peripheral wall of the second half body, and the upper edge of the outer peripheral wall of the second half body can position the top wall of the first half body. A plurality of pins having a receiving seat at a predetermined height position and a tip end that can be elastically fitted into a mounting hole of a printed circuit board on the inner surface of the top wall of the second half body. And a female stud having an escape hole capable of receiving the pin portion of the male stud is provided at a position corresponding to this male stud. Achieved by structure.

Engagement protrusions and engagement recesses are provided on the inner surface and the outer surface of the outer peripheral walls of the two halves facing each other at the time of fitting, and the positions of the two halves are locked by the engagement of both. When the second half body is injection-molded, a tapered hole penetrating the wall surface of the second half body at a predetermined position is formed, and the lead portion of the sheet metal connection terminal that serves as an input / output end of the printed circuit board is externally connected. Then, by press-fitting the lead portion into the inner space of the half body, the lead portion is fixed at a position where it can engage with the through hole of the printed circuit board.

[0011]

Before assembling the housing structure of the present invention, first, the connection terminal is press-fitted into the tapered hole of the second half body to be integrated. Next, the printed circuit board is housed inside the half body through the open surface of the half body, and the mounting hole of the printed circuit board is fitted to the pin portion of the corresponding male stud, and the printed circuit board is mounted on the receiving seat. To position. At that time, since the lead portion of the connection terminal is also inserted into a predetermined through hole of the printed board, this portion is fixed by soldering. Then, the outer peripheral wall of the first half body is fitted to the outer peripheral wall of the second half body containing the printed circuit board and having a shape complementary to this.
The engaging projection and the engaging recess provided on the respective wall surfaces are engaged with each other to lock and integrate them. At this point, the female stud receives the pin portion of the male stud projecting from the mounting hole of the printed circuit board in its escape hole, and the printed circuit board is inserted between the tip surface of the female stud and the receiving seat of the male stud. Both sides are stably clamped to complete the sealed housing structure.

Based on the preferred embodiment shown in the drawings,
The present invention will be described in more detail.

[0013]

FIG. 1 is an exploded perspective view showing the overall construction of an embodiment of the present invention, which is integrally molded of ABS resin or the like.
A first half body 1 composed of a rectangular ceiling wall 1a having an outer dimension of L ₁ × L _{2 and} an outer peripheral wall 1b of a predetermined height extending vertically from a little inner side of the peripheral edge thereof, and also integrally molded with resin. The first half is formed in the closed space of the case main body, which is constituted by the rectangular top wall 2a and the second half 2 including the outer peripheral wall 2b extending vertically from the peripheral edge of the rectangular top wall 2a.
The printed circuit board 3 having a plane size that can be accommodated is accommodated in a region surrounded by the outer peripheral wall of the half body 1. Second
The upper edge of the outer peripheral wall 2b of the half body has the inner dimension M ₁ × M ₂ slightly larger than the dimension L ₁ × L ₂ of the top wall 1a of the first half body. The height is reduced by a height corresponding to the thickness of the top wall 1a of the body, and a step 10 for receiving the top wall 1a is formed over the entire circumference.

The first half 1 has female studs 6 of a predetermined height protruding from the four corner regions of the inner surface of the top wall 1a. The tip surface of the female stud 6 is provided with an escape hole 6a having an inner diameter capable of receiving the tip of a pin portion 4b of a male stud described later. Furthermore, a plurality of engagement recesses 5 are provided at predetermined locations on the outer surface of the outer peripheral wall 1b of the first half body.

On the other hand, on the inner surface of the top wall 2a of the second half body 2, a male stud 4 having a predetermined height is provided at a position corresponding to the female stud 6. The male stud 4 is
As shown in FIG. 2, it is composed of a large-diameter receiving seat 4a and a smaller-diameter pin portion 4b, and is divided into two by a slit 4c from the tip to a predetermined depth. The tip of the pin portion 4b forms a bulging portion having a taper.

On the inner surface of the outer peripheral wall 2b of the outer peripheral wall of the second half body 2, a portion corresponding to the engaging recess 5 of the first half body,
Engagement projections 7 that can be engaged with this are provided. To assemble the housing structure of the present invention having such a configuration, first,
The printed circuit board 3 is housed inside the second half body 2 from the open surface of the second half body 2, and mounting holes 9 drilled at four corners of the printed circuit board 3 are provided with pins of the male stud 4 as shown in FIG. It is fitted to the portion 4b and positioned on the receiving seat 4a. At the time of fitting, the bulging portion at the tip of the pin portion 4b is radially reduced by the slit 4c, is easily inserted into the mounting hole 9, penetrates through the mounting hole 9, and then returns to its original state so that the printed circuit board 3 is Lock it to prevent it from getting out.

In this state, the first half body 1 is applied from above the second half body 2, the outer peripheral walls 1b and 2b of both halves are fitted together, and the step 10 causes the top wall 1a of the first half body to be fitted. Is supported so that the upper surface of the top wall 1a of the first half is flush with the upper end surface of the outer peripheral wall 1b of the second half. At the same time, as shown in FIG. 4, the engaging recesses 5 and the engaging projections 7 on both outer peripheral walls are engaged with each other to lock the mutual positions of the halves 1 and 2 into a case body having a sealed space. It is formed.

At this time, the pin portion 4b penetrating the mounting hole 9 of the printed circuit board and protruding to the opposite side of the printed circuit board 3.
The tip of the printed circuit board 3 is comfortably received in the escape hole 6a of the female stud 6, and the printed circuit board 3 is sandwiched between the receiving seat 4a of the male stud 4 and the tip of the female stud 6. The position is fixed. The divided pin portion 4b of the male stud 4 also has a function of absorbing a relative error between the mounting hole 9 of the printed circuit board and the positions of the studs 4 and 6 based on manufacturing accuracy, and the four corners of the top wall in the plan view. It is desirable that the cuts 4c of the male studs provided on the ridges are diagonal to each other.

In order to further ensure the airtightness of the housing structure of the present invention, the four sides of the top wall 1a of the first half body are shown in FIG.
As shown in, the fin-shaped ribs 17 are provided so as to project over the entire circumference. The fin-shaped ribs 17 elastically deform when the top wall 1a is fitted to the inner surface of the outer peripheral wall 2b of the first half body and closely contact with the inner wall of the first half body, thereby exhibiting a sealing function of blocking the inside of the housing from the external environment.

The hermetically sealed housing of the present invention in which the printed circuit board 3 is housed in this manner has a fastening hole 1 penetrating both halves.
It is fixed to a predetermined location such as the eaves of a house with a screw (not shown) through 1. Next, a novel method of fixing the connection terminal, which is one of the features of the present invention, will be described.

As shown in FIG. 6, the outer surface of the region of the molded second half body 2 close to one side of the ceiling wall 2a is formed stepwise and has a thick wall. A recess 12 for positioning the L-shaped connecting terminal 15 made of a metal plate as an input / output end of the printed board 3 and a slit-like tapered hole 13 penetrating the wall are provided in this portion.

The taper hole 13 is for press-fitting / fixing the rising portion 15b constituting the base of the lead portion 15a of the connection terminal 15 to be inserted into the through hole 14 of the printed circuit board at a predetermined position. Figure 7
As shown in (a) and (b), the width W ₂ and the thickness W ₄ on the inlet side are larger than the width W and the thickness W ₁ of the rising portion 15b, while
The width W ₃ and the thickness W ₅ on the outlet side are set smaller than those on the rising portion.

After the second half 2 is obtained by injection molding, the connection terminal 15 is housed in the recess 12 and the lead portion 15a is press-fitted into the tapered hole 13, so that the rising portion 15b has a wall surface of the tapered hole 13 due to the above dimensional relationship. It bites into and seals it, and both are firmly fixed. At this time, the serrations 16 on the side surface of the rising portion 15b further strengthen this fixing action. Also, the portion 1 that fits in the recess 12
5c has a diamond-shaped projection wider than the width of the recess 12, and this portion bites into the side wall of the recess 12 and is fixed. At this time, the long hole 15d elastically deforms in the compression direction to absorb the stress. 15e is a screw hole for connecting wiring.

This new method of fixing the connection terminals eliminates the work of setting the terminals in the mold as in the case of the conventional insert molding method, thus shortening the molding cycle and reducing the manufacturing cost. it can. In addition, the burrs that tend to occur in insert molding are eliminated,
The defective rate is reduced. In this way, the connection terminal 15 integrated with the second half 2 has a predetermined size of the printed circuit board 3 at the same time when the mounting hole 9 of the printed circuit board 3 and the male stud 4 are fitted in the above-described assembly work. It is inserted into the through hole 14 and then soldered to complete electrical connection as shown in FIG.

In order to make it possible to easily disassemble the housing structure once assembled, according to the present invention, as shown in FIGS. 1 and 8, the upper edge of the outer peripheral wall 2b of the second half body 2 is used. A part of the thin-walled part is cut out, and a tab 18 is projected outwardly at this part. Then, the tab 18 is provided with a sloped cutout 19 that points toward the inside of the half body, and further, in the portion of the top wall 1a of the first half body 1 that faces this when fitting, in the same direction as the cutout 19. An inclined sloped protrusion 20 is provided. The two members 19 and 20 have a positional relationship as shown in FIG. 8 when they are fitted to each other, and a slight gap s is formed between the slopes.

When the housing is disassembled, the tip of a flat-blade screwdriver or the like is inserted into this gap s and the top wall 1a of the first half body is lifted up so that the engagement projection 7 and the engagement recess 5 are engaged with each other. It is possible to separate the two halves 1 and 2 by removing them. The tab 18 is also formed with a fastening hole 11 'for inserting a screw for fixing the housing to the mounting surface.

[0027]

EFFECTS OF THE INVENTION The hermetically sealed housing structure of the present invention allows the first and second halves integrally formed of resin to be fitted together by utilizing the elastic deformation of each part without using any screws. Since they are assembled, the number of assembling steps can be significantly reduced, and the robotization of the process can be dealt with.

At least one joint surface of both halves is provided with fin-shaped ribs over the entire circumference thereof, and deformation of the ribs at the time of fitting seals the gap between the other surfaces, so that the inside of the housing and the external environment are not affected. A closed structure in which is completely cut off is obtained. Since the connection terminal is fixed to the taper hole formed in the half body by press fitting, the drawbacks associated with the insert molding can be eliminated.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a configuration of a sealed housing structure of the present invention.

FIG. 2 is an enlarged side cross-sectional view showing a fitting portion of the housing structure of the present invention before being assembled.

FIG. 3 is an enlarged side cross-sectional view showing the fitting portion after being similarly assembled.

FIG. 4 is an enlarged side sectional view showing a locked state of the engagement protrusion and the engagement recess.

FIG. 5 is an enlarged side cross-sectional view showing a sealing function by fin ribs.

FIG. 6 is a partially enlarged perspective view of the bottom surface of the second half body showing the structure for press-fitting the connection terminal.

FIG. 7 is a sectional view of a tapered hole.

FIG. 8 is a side sectional view showing a structure for disassembling the assembled housing.

FIG. 9 is an exploded perspective view showing a configuration of a conventional closed housing structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... 1st half 1a ... Top wall 1b ... Outer peripheral wall 2 ... 2nd half 2a ... Top wall 2b ... Outer peripheral wall 3 ... Printed circuit board 4 ... Male stud 4a ... Receiving seat 4b ... Pin part 4c ... Slit 5 ... Engagement recess 6 ... Female stud 7 ... Engagement projection 6a ... Escape hole 9 ... Mounting hole 10 ... Step 11 ... Fastening hole 12 ... Positioning recess 13 ... Tapered hole 14 ... Through hole 15 ... Connection terminal 15a ... Lead part 15b ... Rising part 16 ... Sawtooth-like return 17 ... Finate rib 18 ... Tab 19 ... Slope-shaped notch 20 ... Slope-shaped protrusion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hisao Hayashi Inventor Hisao Hayashi 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Fujitsu Limited (72) Satoshi Ikeguchi 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Within the corporation

Claims (6)

[Claims] 1. A ceiling wall (1a, 2a) and an outer peripheral wall (1b, 2)
The first and second halves (1, 2) of the plastic box-type, which are made by injection molding and are surrounded by b) and one of the upper and lower surfaces of which are open, are sealed with their open surfaces facing each other. A case body is formed, the printed circuit board (3) is housed in the inner space, and is positioned and fixed on an appropriate mounting surface by at least one screw penetrating both halves (1, 2). A closed casing structure for an electronic device, wherein the side surface of the top wall (1a) of the first half body (1) and the outer surface of the outer peripheral wall (1b) are the outer peripheral wall of the second half body (2). It has a size that can be fitted to the inner surface of (2b), and the upper edge of the outer peripheral wall (2b) of the second half body (2) can position the top wall (1a) of the first half body (1). Step (10) so that
And a receiving seat (4a) at a predetermined height on the inner surface of the ceiling wall (2a) of the second half body (2) and elastically fitted to the mounting hole (9) of the printed circuit board at the tip. A plurality of male studs (4) having matable pin portions (4b) are provided, and the pin portions () of the male studs (4) are provided at corresponding positions of the first half body (1). 4b) is provided with a female stud (6) having a clearance hole (6a) capable of receiving 4b). 2. A fin-shaped rib capable of being in close contact with the inner surface of the outer peripheral wall (2b) of the second half body (2) during the entire assembly on the side surface of the top wall (1a) of the first half body (1). (17) is provided, The housing structure of Claim 1 characterized by the above-mentioned. 3. Engagement recesses (5) and engagement projections (7) are provided on the outer surface and inner surface of the outer peripheral walls (1b, 2b) of the two halves facing each other at the time of fitting, respectively. 5, 7)
The housing structure according to claim 1, wherein the positions of both halves (1, 2) are locked by the engagement of. 4. A tip (4c) of the pin portion (4b) of the male stud is divided into two (4c) so as to be elastically deformable in a radial direction and is formed thicker than a base portion,
Therefore, the pin portion (4b) is attached to the mounting hole (9) of the printed circuit board.
When it is inserted into the hole (9), the pin (4
The housing structure according to claim 1, wherein the tip of b) is configured to perform a retaining action. 5. When the second half body (2) is injection-molded, a taper hole (13) penetrating a wall surface of a predetermined portion of the second half body (2) is formed, and the printed circuit board (3) is formed. ) Input / output terminal of the sheet metal connection terminal (15) lead portion (1
By press-fitting 5a) from the outside, the lead part (15a) is fixed in a position where it can enter the internal space of the half body (2) and engage with the through hole (14) of the printed circuit board. The housing structure according to claim 1, which is characterized in that. 6. A saw-toothed barb (16) is formed on a side surface of a lead portion (15a) of the connection terminal, and an inner surface of the hole (13) when press-fitted into the tapered hole (13) of a half body. The housing structure according to claim 5, wherein the housing structure is configured to increase an engaging force with the.