JP2005150376A - Case for containing electronic circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a case for containing an electronic circuit board which prevents deterioration of waterproofness at the fixing part of a water repellent filter by preventing liquid carried on the surface of the case from adhering to the fixing part of the water repellent filter. <P>SOLUTION: A hollow protrusion 32 protruding outward is formed on a case 10 such that the hollow section serves as a vent 34, and a cap 38 provided with a water repellent filter 36 is fixed to the end face of the protrusion 32. More specifically, the fixing part of the water repellent filter 36 is provided at a position protruding from the surface of the case. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electronic circuit board housing case, and more particularly to an electronic circuit board housing case in which a water repellent filter is attached to a perforated hole.

  In order to achieve both breathability and waterproofness, a vent hole is drilled in a sealed housing case, and a water repellent filter (a water repellent and oil repellent filter that allows air to pass but not liquid to pass through the perforated vent hole) An electronic circuit board housing case has been proposed in the past.

As such a housing case, for example, a technique described in Patent Document 1 can be cited. In the technique described in Patent Document 1, the water repellent filter (10) is sandwiched by a sealing material (rubber gasket 50), and the sealing material is attached to the case inner wall around the vent hole by a pressing plate (15). The pressing plate (15) and the inner wall of the case are fastened with screws (18) while holding down, so that the water repellent filter (10) is attached to the opening end of the vent on the inner wall side of the case. Further, by forming an annular projecting portion (22) projecting outward from the case around the vent hole, it is configured to suppress the liquid that has transmitted along the case surface from entering the vent hole, The inner wall of the protrusion (22) is tapered, so that the liquid that has entered the vent hole can be easily discharged.
JP 2000-138469 A (paragraph 0036, FIG. 4 etc.)

  However, in the above-mentioned Patent Document 1, since the water-repellent filter is attached to the inner wall of the case via a sealing material (rubber gasket), the liquid that has entered the vent hole is easily attached to the sealing material, In addition, the attached liquid swells the sealing material, which may reduce the waterproofness of the attachment portion of the water repellent filter.

  Accordingly, the object of the present invention is to solve the above-mentioned problems and prevent the liquid transmitted through the case surface from adhering to the attachment portion of the water repellent filter, and thus not reduce the waterproofness of the attachment portion of the water repellent filter. An object of the present invention is to provide a storage case for an electronic circuit board.

  In order to solve the above-mentioned object, according to claim 1, an electronic circuit board is accommodated in an internal space, and an electronic circuit board is accommodated in which a vent hole communicating with the external space is provided. In the case, a hollow projecting portion projecting outward is formed in the housing case to form the vent hole, and a water repellent filter is attached to an end surface of the projecting portion.

  According to a second aspect of the present invention, a first protective wall protruding so as to surround the protruding portion is formed in the vicinity of the protruding portion, and a notch portion having a predetermined width is formed on the first protective wall. At least one place was formed.

  According to a third aspect of the present invention, a second protective wall is formed in the vicinity of the first protective wall so as to protrude opposite the notch.

  According to a fourth aspect of the present invention, the height of the first protective wall is set to be higher than the end face of the water repellent filter attached to the protruding portion.

  According to a fifth aspect of the present invention, the height of the second protective wall is set to be higher than the end face of the water repellent filter attached to the protruding portion.

  In the housing case for an electronic circuit board according to claim 1, a hollow projecting portion projecting outward is formed in the housing case to form a vent hole, and water repellent is formed on an end surface of the projecting portion. Since the filter is mounted, i.e., the water repellent filter mounting portion is provided at a position protruding from the case surface, the liquid that has traveled along the case surface adheres to the water repellent filter mounting portion. Therefore, it is possible to prevent the waterproofness of the attachment portion of the water repellent filter from being lowered.

  In the electronic circuit board housing case according to claim 2, a first protective wall protruding so as to surround the protruding portion is formed in the vicinity of the protruding portion, and the first protective wall is formed. In addition to the above-described effects, the first protective wall prevents the liquid that has traveled along the surface of the case from reaching the protruding portion. In addition, even when the liquid enters the inner peripheral side (projecting portion side) of the first protective wall, it can be easily discharged to the outer peripheral side of the first protective wall through the notch. Therefore, it is possible to more effectively prevent the liquid from attaching to the attachment portion of the water repellent filter, and thus more effectively prevent the waterproofness of the attachment portion of the water repellent filter from being lowered. .

  In the electronic circuit board housing case according to claim 3, the second protective wall is formed in the vicinity of the first protective wall so as to protrude opposite the notch. Therefore, in addition to the above-described effects, the second protective wall can suppress the intrusion of liquid from the notch formed in the first protective wall to the inner peripheral side of the first protective wall. Further, it is possible to more effectively prevent the liquid from adhering to the attachment portion of the water repellent filter, and thus it is possible to more effectively prevent the waterproof property of the attachment portion of the water repellent filter from being lowered.

  In the electronic circuit board housing case according to claim 4, the height of the first protective wall is set to be higher than the end face of the water repellent filter attached to the protruding portion. In addition to the effects described above, the water repellent filter mounting portion provided at a position protruding from the case surface can be prevented from coming into direct contact with the external environment, thereby preventing the water repellent filter from being damaged or detached. Therefore, the waterproofness of the storage case can be further improved.

  In the electronic circuit board housing case according to claim 5, the height of the second protective wall is set to be higher than the end face of the water repellent filter attached to the protruding portion. In addition to the effects described above, the attachment of the water repellent filter provided at a position protruding from the surface of the case can be more effectively prevented from coming into direct contact with the external environment. Since the separation can be more effectively prevented, the waterproofness of the housing case can be further improved.

  The best mode for carrying out the electronic circuit board housing case according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a perspective view of an electronic circuit board housing case according to a first embodiment of the present invention. 2 is a cross-sectional view taken along line II-II in FIG.

  Reference numeral 10 in the figure denotes an electronic circuit board storage case (hereinafter simply referred to as “storage case”). The housing case 10 includes a case main body 12 and a cover 14 attached thereto, and an electronic circuit board 16 (shown in FIG. 2, hereinafter simply referred to as “substrate”) is housed in an internal space formed by them. Note that illustration of the electronic components mounted on the substrate 16 is omitted except for the connector 18.

  The case body 12 is made of a metal having high thermal conductivity such as aluminum, and a connector opening 20 (shown in FIG. 2) into which the connector 18 is to be inserted is formed on the bottom surface.

  A first groove 22 having a predetermined width and depth is formed on the outer periphery of the connector opening 20 over the entire periphery. A plurality of placement portions 24 on which the substrate 16 is to be placed are formed on the side surface of the case body 12. Further, a second groove 26 having a predetermined width and depth is formed on the upper end of the side surface (contact portion with the cover 14) over the entire circumference.

  On the other hand, the cover 14 is also formed of a metal having high thermal conductivity such as aluminum. A first convex portion 30 to be inserted into the second groove portion 26 is formed at the lower end of the side surface of the cover 14 (the contact portion with the case main body 12).

  Near the center of the cover 14, a hollow projecting portion 32 projects outward from the case, and the hollow portion serves as a vent hole 34 that communicates the internal space of the housing case 10 to the outside. Further, a cap 38 having a water repellent filter 36 (a water repellent or oil repellent filter that allows air to pass but does not allow liquid to pass) is attached to the end face of the protruding portion 32. The angle formed between the surface of the cover 14 and the side surface of the protrusion 32 is set to 90 degrees or approximately 90 degrees.

  Further, a first protective wall 40 is provided in the vicinity of the protruding portion 32 so as to protrude outward from the case. Two cutout portions 42 (shown in FIG. 1) having a predetermined width are formed in the first protective wall 40. Further, in the vicinity of the first protective wall 40, two second protective walls 44 are similarly provided protruding outward from the case.

  A plurality of electronic components including the connector 18 are mounted on the board 16 as described above. Further, around the connector 18, the second convex portion 50 to be inserted into the first groove portion 22 is formed.

  Next, the attachment of the substrate 16 to the case body 12 will be described. An adhesive having elasticity (low hardness after curing), for example, a silicon-based adhesive is applied to the first groove portion 22 formed in the case body 12. After applying an appropriate amount, the substrate 16 is placed on the placement portion 24 of the case body 12 and fastened and fixed by screws 52.

  At this time, the connector 18 mounted on the substrate 16 is protruded outward of the case body 12 through the connector opening 20 formed in the bottom surface of the case body 12, and in the first groove 22. The second convex portion 50 is inserted. That is, the connector opening 20 is sealed by bringing the first groove 22 and the second protrusion 50 into close contact with each other via an adhesive.

  After the substrate 16 is attached to the case body 12, the cover 14 is then attached to the case body 12. Specifically, an appropriate amount of an adhesive having elasticity (low hardness after curing), for example, a silicon-based adhesive, is applied to the second groove 26 formed in the case body 12, and then the second groove 26. The first convex portion 30 is inserted into and fixed by a screw 54 (shown in FIG. 1). In other words, the second concave portion 26 and the first convex portion 30 are brought into close contact with each other through the adhesive, whereby the internal space of the housing case 10 in which the substrate 16 is to be housed is sealed.

  FIG. 3 is an enlarged partial plan view of the housing case 10 as viewed from the cover 14 side. 4 is a cross-sectional view taken along line IV-IV in FIG. 3, and FIG. 5 is a cross-sectional view taken along line VV in FIG. Hereinafter, the structure of the cap 38 will be described in detail with reference to FIGS.

  The cap 38 is formed from a resin material such as polybutylene terephthalate (PBT). As shown in FIGS. 4 and 5, the cap 38 includes a filter attachment portion 38 a that has an annular shape (annular shape in plan view) having the same diameter as the protruding portion 32, and the filter attachment portion 38 a has a circular shape (circular shape in plan view). ) Is attached.

  In addition, the cap 38 includes a filter protection part 38b having a circular shape (circular in plan view) having the same diameter as the filter mounting part 38a. The filter protection part 38b is formed at a predetermined distance from the filter attachment part 38a via a plurality of support members 38c. That is, the water repellent filter 36 is covered with the filter protection portion 38a and protected from the external environment, and a predetermined gap (space) that allows air to enter and exit between the water repellent filter 36 and the filter protection portion 38b. Is formed.

  Further, the cap 38 includes a plurality of elastically deformable snap fits 38d. The plurality of snap fits 38d are respectively formed continuously to the filter attachment portion 38a so as to draw an arc having the same diameter as the vent hole 34.

  The cap 38 inserts the snap fit 38d into the insertion hole 34 and engages the claw portion with the inner wall of the cover 14, so that the protrusion 32 and the O-ring 60 (the back surface of the claw portion and the filter attachment portion 38a). Is attached to the end face of the protruding portion 32. Thereby, the end surface of the protrusion 32 (the opening end of the vent hole 34) is sealed by the water repellent filter 36.

  As described above, in this embodiment, the case main body 12 and the cover 14 are attached in an airtight manner using an adhesive, and the cover 14 is formed with a vent hole 34 that allows the internal space of the housing case 10 to communicate with the outside. In addition, a water-repellent / oil-repellent water-repellent filter 36 is attached to the opening end of the vent hole 34 to achieve both waterproofness (dustproofness) and air permeability.

  In addition, the water repellent filter 36 (more specifically, the cap 38 including the water repellent filter 36) is configured to be attached to the end face of the protruding portion 32 protruding outward from the case, in other words, the water repellent filter 36. Is provided at a position protruding from the surface of the case, so that the liquid transmitted through the case surface (the surface of the cover 14) is attached to the water repellent filter 36 (specifically, the end surface of the protruding portion 32). And the O-ring 60, the back surface of the filter mounting portion 38a, etc.) can be prevented. For this reason, even when the water repellent filter 36 is attached to the housing case 10 via a sealing material such as an O-ring 60, the sealing material does not swell. It is possible to prevent deterioration of waterproofness.

  Next, the first protective wall 40 and the second protective wall 44 described above will be described in detail with reference to FIGS.

  A first protective wall 40 that protrudes so as to surround the protrusion 32 is formed in the vicinity of the protrusion 32. The first protective wall 40 has a height equal to or higher than the end face of the water repellent filter 36 attached to the protrusion 32, more specifically, the end face of the cap 38 including the water repellent filter 36 (filter protection). The height is set to be higher than the end face of the portion 38b (so as to protrude outward from the case).

  Further, the first protective wall 40 is formed with two notches 42 having a predetermined width at opposing positions. That is, the first protective wall 40 is formed by being divided into two wall pieces. The first protective wall 40 divided into two wall pieces is formed in an arc shape (substantially semicircle) having the same radius centered on the protruding portion 32.

  In addition, two second protective walls 44 are formed in the vicinity of the first protective wall 40 so as to protrude so as to face the respective notches 42. The width of the second protective wall 44 is formed to be larger than the width of the cutout portion 42 (that is, the separation distance between two wall pieces constituting the first protective wall 40). Further, the side surface (indicated by reference numeral 44a in FIG. 3) of the second protective wall 44 that does not face the notch 42 is formed in an arc shape. Note that the height of the second protective wall 44 is also higher than the end face of the water repellent filter 36 attached to the protrusion 32, more specifically, the end face of the cap 38 (the end face of the filter protector 38b). ) It is set to the above height.

  The storage case 10 is such that one of the two cutout portions 42 formed in the first protective wall 40 is below the protruding portion 32 (that is, the water repellent filter 36) in the direction of gravity. In addition, it shall be fixed to the attachment target.

  Thus, in this embodiment, the first protective wall 40 that protrudes so as to surround the protruding portion 32 is formed in the vicinity of the protruding portion 32, so that the first protective wall 40 is attached to the housing case 10. The first protective wall 40 can suppress the liquid that has traveled along the case surface (the surface of the cover 14) from reaching the protrusion 32. In other words, the liquid that has traveled along the surface of the case can be dropped downward of the case while avoiding the attachment portion of the water repellent filter 36. Further, since the notch 42 is formed in the first protective wall 40, as shown in FIG. 6, even when the liquid enters the inner peripheral side (projecting part 32 side) of the first protective wall 40. In addition, since it can be easily discharged to the outer peripheral side of the first protective wall 40 through the notch portion 42 located below the protrusion 32 (downward in the direction of gravity), the attachment of the water repellent filter 36 It is possible to more effectively prevent the liquid from adhering to the portion, and thus it is possible to more effectively prevent the waterproofness of the attachment portion of the water repellent filter 36 from being lowered.

  Furthermore, since the second protective wall 44 is formed in the vicinity of the first protective wall 40 so as to protrude opposite the notch portion 42, the second protective wall 44 is attached to the housing case 10 and has been transmitted along the surface of the case. As shown in FIG. 7, the liquid drops on the outer peripheral surface of the first protective wall 40 along the side surface 44 a of the second protective wall 44, and further passes along the outer peripheral surface of the first protective wall 40. 10 downward (downward in the direction of gravity). In other words, the second protective wall 44 prevents the liquid from entering the inner peripheral side of the first protective wall 40 from the notch 42 positioned above the protrusion 32 (downward in the direction of gravity). be able to. Thereby, it is possible to more effectively prevent the liquid from adhering to the attachment portion of the water repellent filter 36, and thus more effectively prevent the waterproof property of the attachment portion of the water repellent filter 36 from being lowered. Can do.

  Further, the height of the first protective wall 40 and the second protective wall 44 is equal to or higher than the end surface of the water repellent filter 36 attached to the protrusion 32 (more specifically, the end surface of the cap 38 including the water repellent filter 36). Therefore, the attachment portion of the water repellent filter 36 provided at a position protruding from the surface of the case can be prevented from coming into direct contact with the external environment, so that the water repellent filter 36 is damaged or detached. Since (breakage and detachment of the cap 38) can be prevented, the waterproofness of the housing case 10 can be further improved.

  In the above description, the two cutout portions 42 are formed in the first protective wall 40. However, the number of the cutout portions 42 may be one or three or more. In any case, it goes without saying that the housing case 10 is fixed to the attachment target so that at least one of the notches 42 is located below the protrusion 32 in the direction of gravity. It should be noted that the second protective wall 44 facing the notch portion 42 positioned below the protrusion 32 in the direction of gravity may not be formed.

  Further, although the water repellent filter 36 is attached to the cap 38 and the cap 38 is attached to the end surface of the protruding portion 32, the water repellent filter 36 may be directly attached to the end surface of the protruding portion 32.

  As described above, in the first embodiment of the present invention, the electronic circuit board (16) is accommodated in the internal space, and the vent hole (34) communicating the internal space to the outside is formed. In the electronic circuit board housing case (10), the housing case (10) is formed with a hollow projecting portion (32) projecting outwardly to form the vent hole (34). The water repellent filter (36) was attached to the end face of the portion (32).

  In addition, a first protective wall (40) protruding so as to surround the protruding portion (32) is formed in the vicinity of the protruding portion (32), and the first protective wall (40) has a predetermined width. At least one notch (42) was formed.

  Further, a second protective wall (44) is formed in the vicinity of the first protective wall (40) so as to protrude opposite the notch (42).

  Further, the height of the first protective wall (40) is set to the end face of the water repellent filter (36) attached to the protrusion (32) (more specifically, the cap to which the water repellent filter (36) is attached). (38) (End face) It was configured to set the height above.

  Further, the height of the second protective wall (44) is set so that the end surface of the water repellent filter (36) attached to the protrusion (32) (more specifically, a cap to which the water repellent filter (36) is attached). (38) (End face) It was configured to set the height above.

1 is a perspective view of a housing case for an electronic circuit board according to a first embodiment of the present invention. It is the II-II sectional view taken on the line of FIG. It is the expansion partial top view which looked at the storage case shown in FIG. 1 from the cover side. It is the IV-IV sectional view taken on the line of FIG. It is the VV sectional view taken on the line of FIG. It is a top view explaining the flow of the liquid adhering to the storage case shown in FIG. FIG. 7 is a plan view similar to FIG. 6 for explaining the flow of liquid attached to the storage case shown in FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Storage case 16 Electronic circuit board 32 Protrusion part 34 Ventilation hole 36 Water repellent filter 38 Cap 40 1st protection wall 42 Notch part 44 2nd protection wall

Claims (5)

  In an electronic circuit board housing case in which an electronic circuit board is housed in an internal space and a vent hole is formed to communicate the internal space with the outside, a hollow projecting outward from the housing case. A housing case for an electronic circuit board, wherein the projecting portion is formed to form the vent and a water repellent filter is attached to an end face of the projecting portion.   A first protective wall protruding so as to surround the protruding portion is formed in the vicinity of the protruding portion, and at least one notch portion having a predetermined width is formed in the first protective wall. The electronic circuit board housing case according to claim 1.   3. The electronic circuit board housing case according to claim 2, wherein a second protective wall is formed in the vicinity of the first protective wall so as to protrude opposite the notch. 4.   4. The electronic circuit board housing case according to claim 2, wherein a height of the first protection wall is set to be equal to or higher than an end face of the water repellent filter attached to the projecting portion.   5. The electronic circuit board housing case according to claim 3, wherein a height of the second protective wall is set to be equal to or higher than an end surface of the water repellent filter attached to the projecting portion.

Images