JP6576692B2 - FOT shield case - Google Patents

Description

  The present invention relates to a shield case of FOT (Fiber Optic Transceiver) used for optical communication.

  The FOT used for optical communication is stored in a shield case made of metal for shielding electromagnetic noise so that the operation is not hindered by electromagnetic noise such as electromagnetic waves generated from electric devices in the vicinity (patent) Reference 1).

JP-A-2005-266130

  The above-mentioned shield case is formed in a rectangular tube shape having an open portion on one side so that the FOT formed in a rectangular flat block shape can be accommodated. To be assembled.

  This shield case is constructed by sequentially bending case materials. In detail, the case material has a developed shape in which the peripheral wall corresponding to the body of the shield case is connected in one direction, and a bent piece extending in a direction orthogonal to this one direction (a closed end opposite to the open portion) Is added. Such a case material is formed by punching from a metal plate.

  However, the bent piece that forms the closed end of the shield case tends to spring back and the free end of the bent piece is lifted. Noise may enter the case and the electromagnetic resistance of the FOT may be impaired.

  Therefore, the present invention provides a shield case that can prevent the generation of a gap due to the floating of the bent piece constituting the closed end of the shield case and can increase the electromagnetic resistance of the FOT.

The shield case of the FOT according to the present invention is a metal shield case that is formed in a rectangular tube shape with one side as an open part, and is fitted and assembled from the open part to the FOT, The shield case is a bent piece in which a closed end facing the open portion is extended to an edge of at least one side wall of the peripheral wall of the case body, and is bent at a substantially right angle from a base which is the base of the extension. A holding portion for restraining the free end portion of the bent piece is provided at the edge of the other side wall of the peripheral wall of the case body portion, and the bent piece of the peripheral wall of the case body portion is provided. The side wall is divided into two at the circumferential central portion thereof and is configured as a side wall element provided with the bent piece, and sleeve pieces having substantially the same length are provided at both circumferential edges of the side wall element. The sleeve pieces are folded at a substantially right angle in the case inward direction and overlapped. And characterized in that it constitutes a.

According to the shield case of the FOT according to the present invention, the free end portion of the bent piece is constrained by the presser portion, the lifting due to the spring back is suppressed, and the generation of a gap at the closed end of the shield case can be prevented. And the electromagnetic resistance of the FOT can be maintained well. Furthermore, when two independent FOTs on the light receiving side and the light emitting side are housed in a single shield case and arranged side by side, mutual interference between the light receiving and light emitting signals of each FOT can be avoided by the partition wall, and reliability Can be increased. Moreover, since the partition can be configured with sleeve pieces extending on the two-sided side wall elements, the design is easy, especially when the shield case is formed by stamping and forming as a case material of a required unfolded shape with a single metal plate. It is valid.

Further, in the FOT shield case according to the present invention, the presser portion is extended to an edge of the other side wall of the peripheral portion of the case body portion, and the closed end is configured from a base portion that is the base of the extension. It is preferable that the holding piece is formed of a presser piece that is bent at a substantially right angle and overlapped over the free end of the bent piece.

  According to the shield case of this FOT, since the presser part is extended to the edge of the other side wall of the peripheral wall of the case body part, the presser part can be integrated with the other part of the shield case and is made of a separate member. This eliminates the need for a dedicated presser portion, which is advantageous in terms of cost. In addition, since the presser part is composed of a presser piece that is folded at a substantially right angle and overlapped on the free end part of the bent piece, the presser function can be exerted over the free end and the case on the free end side Since the gap is closed, the shielding function can be improved.

  In the FOT shield case according to the present invention, it is preferable that the pressing piece is set to an extension width shorter than the extension width of the bent piece.

  According to the shield case of this FOT, when the shield case is formed by punching and forming a single metal plate as a case material having a required developed shape, the shield case is within the area of the side portion where the bent piece of the metal plate is punched. Since the presser piece can be stamped and formed together with the bent piece, the manufacturing cost can be reduced without increasing the width of the metal plate.

  According to the present invention, the free end portion of the bent piece is constrained by the presser portion, the lifting due to the springback is suppressed, and it is possible to prevent a gap from being generated at the closed end of the shield case. The mechanical resistance can be maintained well.

It is a perspective view which decomposes | disassembles and shows 1st Embodiment of FOT which concerns on embodiment of this invention, and its shield case. It is expansion | deployment explanatory drawing of the shield case shown in FIG. It is a perspective view which shows 2nd Embodiment of a shield case. It is sectional drawing which follows the AA line of FIG. It is an expansion explanatory view of the shield case shown in FIG.

  Hereinafter, the present invention will be described according to preferred embodiments, but the present invention is not limited to the embodiments described below, and can be appropriately changed without departing from the spirit of the present invention.

  FIG. 1 is an exploded perspective view showing a first embodiment of an FOT and its shield case according to an embodiment of the present invention. FIG. 2 is a developed plan view of the shield case shown in FIG. The FOT 1 of the first embodiment shown in FIG. 1 is configured independently on the light emitting side and the light receiving side.

  Each FOT 1 on the light-emitting side and the light-receiving side is mainly composed of a resin package 2 formed in a square flat block shape, and a plurality of lead pins 3 constituting a lead frame at a pair of opposite ends thereof and a grounding conductive material. The metal plate is integrally molded with the ear piece 4 protruding outward.

  On the front side of the package 2, a light transmitting hole 5 is formed on the optical axis of a light guide member to which an optical fiber (not shown) is connected. The package 2 has a built-in sub circuit board on which a light emitting element or a light receiving element is mounted, and the light receiving element or the light emitting element on the sub circuit board receives and emits an optical signal through the light transmitting hole 5. ing.

  In the example shown in FIG. 1, the FOT 1 is mounted upright on a main circuit board (not shown) together with a shield case 6 for shielding electromagnetic noise. For this reason, the above-mentioned lead pin 3 protrudes downward from the lower end portion of the package 2 and is soldered onto the main circuit board. On the other hand, the FOT 1 has a configuration in which the above-mentioned pair of ear pieces 4 are disposed so as to protrude upward from each other in the longitudinal direction of both ends of the upper end portion of the package 2. The ear piece 4 protrudes upward from the upper end surface of the package 2 due to manufacturing reasons.

  On the other hand, the shield case 6 is formed in a rectangular tube shape whose lower side is open. The shield case 6 is externally inserted from the upper end side where the ear piece 4 of the package 2 protrudes from the FOT 1. As a result, the FOT 1 is accommodated in the shield case 6 and entirely covered so as to block external electromagnetic noise generated in the vicinity.

  A light transmitting hole 7 corresponding to the light transmitting hole 5 of the FOT 1 is opened on the front surface of the shield case 6, and a plurality of grounding legs that also serve as a fixing to the main circuit board are provided at the periphery of the lower open part. 8 is provided.

  As shown in FIGS. 1 and 2, the upper closed end 10 facing the lower open portion of the shield case 6 extends to the edge of at least one side wall 11a of the peripheral wall 11 of the case body. The bent piece 12 is bent at a substantially right angle from the extended base.

  On the other hand, a holding portion 13 that restrains the free end portion of the bent piece 12 is provided at the edge of the other side wall 11 b of the peripheral wall 11 of the case body portion.

  In the present embodiment, the bent piece 12 described above is extended to the upper end edge of the front side wall 11a of the peripheral wall 11 of the case body. On the other hand, the presser portion 13 extends to the upper end edge of the rear side wall 11b. For this reason, the presser part 13 is composed of a presser piece 14 which is bent and overlapped at a substantially right angle from the extended base part to the free end part of the bent piece 12.

  The extending width W2 of the pressing piece 14 is set to be shorter than the extending width W1 of the bent piece 12 (W1> W2) (see FIG. 2).

  Such a shield case 6 is configured by sequentially bending case material 21 formed by punching from one band-shaped metal plate 20. Such a case material 21 has a shape in which a front side wall 11a, a rear side wall 11b, and left and right side walls 11c and 11d, which are peripheral walls 11 of the case body, are developed in one direction. The bent piece 12, the presser piece 14 and the like are added. Then, the peripheral wall 11, the bent piece 12 and the holding piece 14 are sequentially bent from the case material 21 by a roll process or the like at a substantially right angle from the section position indicated by the alternate long and short dash line in FIG. It can be formed in a cylindrical shape.

  In the example shown in FIG. 2, the leaf spring piece 15 is cut and raised on the rear side wall 11b of the peripheral wall 11 of the case body, and when the shield case 6 is externally inserted into the FOT 1 and assembled, The back surface of the package 2 is pressed against the light transmitting hole 5 and held.

  In this manner, according to the shield case 6 of the FOT 1 according to the present embodiment, the free end portion of the bent piece 12 of the front side wall 11a is restrained by the presser portion 13, and lifting due to the springback is suppressed. Accordingly, it is possible to prevent a gap from occurring at the closed end 10 of the shield case 6 and to maintain the electromagnetic resistance of the FOT 1 well.

  Further, since the presser portion 13 is extended to the edge of the other side wall 11b of the peripheral wall 11 of the case body portion, the presser portion 13 can be integrated with the other portions 10 and 11 of the shield case 6, and from a separate member. This eliminates the need for a dedicated presser portion, which is advantageous in terms of cost. In addition, since the presser portion 13 is composed of a presser piece 14 that is bent at a substantially right angle and overlapped over the free end portion of the bent piece 12, the presser portion 13 can exhibit a presser function over the free end, This closes the case gap on the side and improves the shielding function.

  Further, since the holding piece 14 is set to an extension width W2 that is shorter than the extension width W1 of the bent piece 12, the shield case 6 is punched out as a case material 21 having a required developed shape with a single metal plate. In the case of forming and forming, since the presser piece 14 can be punched and formed together with the bent piece 12 within the area of the side portion where the bent piece 12 of the metal plate 20 is punched out, the manufacturing cost does not accompany the widening of the metal plate. Can be suppressed.

  Next, a second embodiment of the present invention will be described. The shield case according to the second embodiment is the same as that of the first embodiment, but the configuration is partially different. Hereinafter, differences from the first embodiment will be described.

  FIG. 3 is a perspective view showing a second embodiment of the shield case, and FIG. 4 is a cross-sectional view taken along the line AA of FIG. FIG. 5 is a development explanatory view of the shield case shown in FIG.

  First, in the first embodiment, the shield case 6 has an independent configuration for accommodating the light receiving side and the light emitting side FOT 1. On the other hand, the shield case 6A according to the second embodiment has a horizontally long structure in which the two FOTs 1 on the light receiving / emitting side are accommodated in one shield case 6A as shown in FIGS. .

  For this reason, in the shield case 6A of the second embodiment, two light transmitting holes 7 corresponding to the light transmitting holes 5 and 5 of the two FOTs 1 on the light receiving / emitting side are formed on the two front side walls 11a of the peripheral wall 11 of the case body. , 7 are provided.

Further, particularly in the present embodiment, the front side wall 11a is divided into two at the central portion in the length direction (the circumferential direction of the peripheral wall 11), and two side wall elements 11a ₁ and 11a ₂ each having a bent piece 12 at the upper edge are provided. The sleeve piece 16 is extended in each of those division | segmentation edge (circumferential direction edge) (refer FIG. 5). Then, these two sleeve pieces 16 are bent substantially perpendicularly to the inside of the case and overlapped in a back-to-back manner to constitute a partition wall 17 that divides the receiving / emitting side two FOT 1 storage portions (FIG. 4). reference).

  In this way, according to the shield case 6A according to the second embodiment, the electromagnetic resistance of the FOT 1 can be maintained well as in the first embodiment. In addition, a dedicated presser portion made of a separate member is not required, which is advantageous in terms of cost, and the case clearance on the free end side is closed, thereby improving the shield function. In addition, the manufacturing cost can be reduced without increasing the width of the metal plate.

  In addition, according to the second embodiment, when two independent FOTs 1 on the light receiving side and the light emitting side are accommodated in one shield case 6A and arranged side by side, the partition wall 17 allows the reception / emission signal of each FOT 1 to be received. Mutual interference can be avoided and reliability can be improved. Moreover, since the partition wall 17 can be constituted by the sleeve pieces 16 extending on the two side wall elements, the design is easy. In particular, the shield case 6A is stamped and formed as a case material 21 having a required unfolded shape with a single metal plate 20. This is effective when configured.

  As described above, the present invention has been described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and modifications may be made without departing from the spirit of the present invention. You may combine the technique as described in a form.

  For example, in the above embodiment, the example in which the bent piece 12 is extended to the upper end edge of the front side wall 11a and the presser piece 14 is extended to the upper end edge of the rear side wall 11b has been described. Each may be extended other than the side wall 11b. In addition, the bent piece 12 may be extended from the plurality of side walls 11, and the pressing portion 13 may be extended from the plurality of side walls 11. For example, the folded piece 12 is extended to the upper end edge of the front side wall 11a and the upper end edges of the left and right side walls 11c and 11d to form the closed end 10 and extended to the upper end edge of the rear side wall 11b. You may make it restrain the free end part of the three bending pieces 12 simultaneously with the one pressing piece 14. FIG. Furthermore, the presser portion 13 may be formed of a separate material.

  In the second embodiment, two sleeve pieces 16 are provided. However, the present invention is not limited to this, and one sleeve piece 16 may be provided. Furthermore, in the said embodiment, although FOT1 has shown the thing of the type which was respectively independent by the light-receiving side and the light emission side, it is not restricted to this, It can also apply to what was comprised as a light-receiving / light-emitting part side type. It is.

1 ... FOT
DESCRIPTION OF SYMBOLS 2 ... Package 3 ... Lead pin 5 ... Translucent hole 6, 6A ... Shield case 7 ... Translucent hole 8 ... Grounding leg part 10 ... Closed end 11 ... Peripheral wall 11a ... Front side wall (one side wall)
11a ₁ , 11a ₂ ... divided side wall elements 11b ... rear side wall (other side wall)
DESCRIPTION OF SYMBOLS 12 ... Bending piece 13 ... Pressing part 14 ... Holding piece 16 ... Sleeve piece 17 ... Partition 20 ... Metal plate 21 ... Case material W1 ... Extension width of bending piece W2 ... Extension width of holding piece

Claims (3)

A metal shield case that is formed in a rectangular cylinder shape with one side as an open part and is assembled by being externally inserted and inserted into the FOT from the open part,
The shield case is a bent piece in which a closed end facing the open portion is extended to an edge of at least one side wall of the peripheral wall of the case body, and is bent at a substantially right angle from a base which is the base of the extension. Consisting of
At the edge of the other side wall of the peripheral wall of the case body, a pressing part for restraining the free end of the bent piece is provided ,
The side wall provided with the bent piece of the peripheral wall of the case body is configured as a side wall element provided with the bent piece divided into two at the circumferential center portion thereof,
A partition wall is formed by extending sleeve pieces having substantially the same length at both circumferential edges of the side wall elements, and bending and overlapping the sleeve pieces at a substantially right angle in the case inward direction. FOT shield case. The pressing portion extends from the base of the other side wall of the peripheral wall of the case body portion to the free end of the bent piece that forms the closed end from the base that is the root of the extension. The shield case for FOT according to claim 1, wherein the shield case is formed of a presser piece that is bent at a substantially right angle and overlapped. The shield case for FOT according to claim 2, wherein the pressing piece is set to an extension width shorter than an extension width of the bent piece.

Images