JP5062107B2 - Electronic device housing structure - Google Patents

Description

  The present invention relates to a housing structure of an electronic device including a printed board on which a connector is mounted, a case for housing the printed board, and a cover.

  An electronic control unit (ECU, Electric Control Unit) is disposed in the engine room of the vehicle to perform various controls of the vehicle. Such a housing structure of an electronic device used for an ECU of a vehicle is disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-258450 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2005-150545 (Patent Document 2).

The components of the ECU can be roughly classified into a printed circuit board on which electronic components are mounted, a box-shaped resin case that houses the printed circuit board, a connector for connecting to the outside, and a resin cover that covers the opening of the case. In the case of a waterproof structure, an annular packing is inserted between the case and the cover. In recent years, a connector built-in cover in which a connector and a cover are integrated has been used. In addition, a screw has been conventionally used for coupling the case and the cover, but in recent years, snap-fit coupling that is easy to assemble is frequently used.
JP 2003-258450 A JP 2005-150545 A

  FIGS. 8 and 9 are diagrams showing a conventional ECU 90 in which the connector built-in cover and the snap-fit coupling are used. FIG. 8A is a top view of the appearance of the ECU 90, and FIG. 8B is a side view of the appearance of the ECU 90. FIG. 9 is an enlarged cross-sectional view of the portion indicated by the alternate long and short dash line A in FIG. 8, and is a diagram schematically showing a housing structure for coupling and waterproofing of the case 10 and the connector built-in cover 20 in the ECU 90. .

  The ECU 90 shown in FIGS. 8 and 9 incorporates a box-shaped case 10 having an opening on the front surface that accommodates a printed circuit board (not shown) on which electronic components are mounted, and a connector coupled to the printed circuit board. A connector built-in cover 20 that covers the opening of the case 10 and an annular packing 30 that is inserted and disposed between the case 10 and the connector built-in cover 20 are provided. The case 10 and the connector built-in cover 20 are fixed by snap-fit coupling via a claw F10 provided on the case 10 side and a protrusion F20 provided on the connector built-in cover 20 side.

  As shown in FIG. 9, the packing 30 has a cross-sectional shape in which two protrusions 30t are formed on parallel long sides of a substantially oval cross section. In addition, an annular convex portion 11 having a protruding cross-sectional shape is formed on the front surface of the case 10, and the connector built-in cover 20 has an annular concave shape having a recessed sectional shape having two bottom surfaces 21a and 21b. A portion 21 is formed. And the front-end | tip of the convex part 11 of the case 10 fits and positions to the bottom face 21b in the concave part 21 of the connector built-in cover 20, and the side surface around it. Further, the packing 30 is inserted and disposed in a space K1 formed by the outer peripheral side surface of the convex portion 11 of the case 10 and the bottom surface 21a of the concave portion 21 of the connector built-in cover 20 and the side surface around it, and the protrusion 30t of the packing 30 Is in contact with the side surfaces of the convex portion 11 and the concave portion 21 so that the inside of the ECU 90 is sealed.

  As described above, the housing structure of the ECU 90 shown in FIGS. 8 and 9 uses snap-fit coupling that is easy to assemble for coupling between the case 10 and the connector built-in cover 20. It is also waterproof. On the other hand, in the case structure of the ECU 90, the case 10 and the connector built-in cover 20 shown in FIG. 9 are used to ensure that the claw F10 on the case 10 side is securely fitted to the protrusion F20 on the connector built-in cover 20 side by snap fit. It is necessary to set three gaps S1 to S3 in the assembling direction. Since the gaps S1 to S3 remain even after assembly, the gaps S1 to S3 rattle between the case 10 and the connector built-in cover 20, and when the ECU 90 receives vibration from the outside, the snap-fit joint portion fatigues and breaks. Or an impact sound may be generated. Further, when the case 10 and the connector built-in cover 20 are assembled, the packing 30 is likely to be rolled by friction, and there is a possibility that the arrangement is not correct. On the other hand, if the gap between the side surfaces of the case 10 forming the space K1 and the connector built-in cover 20 is widened to avoid the twisting, the compression of the packing 30 may be loosened and the waterproofness may be impaired.

  Therefore, the present invention is a housing structure of an electronic device having a waterproof packing and in which a case and a connector built-in cover are snap-fit coupled, and suppresses rattling between the case and the connector built-in cover, and is snap-fit coupled An object of the present invention is to provide a housing structure for an electronic device that suppresses fatigue failure of a part and that can be easily assembled and ensure sufficient waterproofness.

According to the first aspect of the present invention, there is provided a box-like case having an opening provided on the front surface for accommodating a printed circuit board on which an electronic component is mounted, and a connector coupled to the printed circuit board. A cover with a built-in connector for covering, and an annular packing that is inserted and arranged around the opening of the case and between the cover with a built-in connector, and the case and the connector built-in cover are fixed by snap-fit coupling. An annular structure having a cross-sectional shape protruding from either the periphery of the opening of the case or the cover with a built-in connector in a fixing direction by the snap-fit coupling perpendicular to the front surface of the case. And a cross-sectional shape that fits into the convex portion is recessed around the opening of the case or the other side of the connector built-in cover. Will be the concave portions of the annular are formed on the outer periphery of the concave portion formed in said annular, the snap-fit coupling is disposed, the packing is a cross-sectional shape is U-shaped, said U-shaped round The thickness of the protruding bottom part is set to be thicker than the thickness of the U-shaped side part, and the rounded protrusion is formed on both sides of the outer side part, which is the side close to the snap-fit coupling of the U-shaped packing. Each of the protrusions is set to be thinner than the thickness of the bottom part, the U-shaped packing covers the periphery of the tip of the convex part, and between the tip surface of the convex part and the bottom surface of the concave part. The bottom part of the packing is inserted and arranged, and the case and the connector built-in cover are fixed by the snap-fit coupling, so that the round protruding bottom part of the packing is crushed and a waterproof seal is provided between the case and the connector built-in cover. It is characterized in that it comprises Te.

  In general, when using a snap-fit coupling consisting of a combination of elastic claws and projections, the claws provided on one side are securely fitted to the other projections when assembling two objects to be fastened. Therefore, it is necessary to set a gap in the fixing direction by snap-fit coupling. The gap between the objects to be fastened in the fixing direction of the snap-fit connection usually remains after the two objects to be fastened by the snap-fit connection. For this reason, in the case structure of an electronic device in which the conventional case and the connector built-in cover are fixed by snap-fit coupling, the case and the connector built-in cover are rattled, resulting in fatigue damage and impact sound generation at the snap-fit coupling portion. It is easy to become.

On the other hand, in the case structure described above, the cross-sectional shape is U-shaped between the front end surface of the convex portion and the bottom surface of the concave portion to be fitted to the case to be fastened and the connector built-in cover in the fixing direction of the snap-fit coupling. A packing having a U-shaped round protruding bottom portion set to be thicker than a side portion is inserted and disposed. The U-shaped packing covers the periphery of the tip of the convex portion, and the bottom portion is disposed between the tip surface of the convex portion and the bottom surface of the concave portion. Further, in the packing, in a state where the case and the connector built-in cover are snap-fit joined, the round protruding bottom portion of the packing is crushed and compressed in the fixing direction. For this reason, even when the gap is set in the fixing direction in order to securely fit the claw and the protrusion provided in the case and the connector built-in cover, repulsive force of the bottom of the compressed gasket is inserted between the bottom surface of the concave portion, it is possible to suppress the rattling of the case and the connector internal cover. Therefore, even when an external force or vibration is applied to the electronic device, it is possible to suppress the occurrence of fatigue failure and impact sound at the snap-fit joint. It goes without saying that the waterproofness inside the electronic device is also secured by the packing.

  As described above, the casing structure of the electronic device is a casing structure of an electronic device having a waterproof packing and in which the case and the connector built-in cover are snap-fit coupled. As a result, it is possible to provide a housing structure for an electronic device that can be easily assembled and ensure sufficient waterproofness.

Further, the housing structure of the electronic device is a cross-sectional shape is U-shaped path Kkin, the tip about the convex portions that are configured to become covered by the U-shaped packing.

State I by this, the cross-sectional shape at the tip of the convex portion (rib) is so as to put the U-shaped packing, placing the pre-packing in one of the opening or around the connector internal cover of the case Assemble the case and the cover with built-in connector, and fix them by snap-fit connection . For this reason, it is easy to assemble the packing, and the packing can be prevented from being twisted or arranged poorly, so that highly accurate assembly can be realized.

Further, in the housing structure of the electronic device, the thickness of the rounded protruding U-shaped bottom of the packing, the are a U-shaped measuring portion is set larger than the thickness construction of the. What I thereto, with rounded protruding bottom of the U-shaped packing thickened set located between the bottom surface of the front end surface and the concave portion of the convex portion, reliably waterproof seal between case and the connector internal cover In addition, rattling between the case in the fixing direction and the connector built-in cover due to the snap-fit connection can be reliably suppressed.

Further, in the housing structure of the electronic device, protrusions set to be thinner than the thickness of the bottom portion protruding round on both sides of the outer side portion that is the side close to the snap-fit coupling of the U-shaped packing , each have a formed comprising configuration.

On both sides of the outer side is the side close to the snap-fit connection of the U-shaped packing as mentioned above, by respectively forming the rounded protruding bottom projection which is set thinner than the thickness of the case and the connector internal cover In a state in which the gasket is snap-fit, each of the protrusions formed on both sides of the outer side as well as the U-shaped bottom located between the front end surface of the convex portion and the bottom surface of the concave portion. Can also be set to be compressed. As a result, not only the fixing direction of the snap-fit connection but also the hooking direction of the snap-fit connection perpendicular to the snap-fit connection can generate a repulsive force by the projection and push up the hook part. For this reason, it is possible to suppress backlash in the hooking direction of the nail, for example, deformation of the case and the connector built-in cover due to external force or environmental load makes the snap-fitting of the snap-fit coupling portion shallow, and the nail is easily detached. Can be prevented.

In this case, as described in claim 2 , for example, the protrusion can be formed in an annular shape along the outer side portion. According to this, in addition to suppressing the play in the hooking direction of the nail by the protrusion, the protrusion can be provided with a sealing function for waterproofing. For this reason, the sealing function can be multiplexed between the bottom of the U-shaped packing and the protrusion located between the front end surface of the convex portion and the bottom surface of the concave portion, and the reliability against waterproofing is further increased. be able to.

In addition, when it is not necessary to multiplex the sealing function for waterproofing, as described in claim 3 , the protrusion is a snap between the case and the connector built-in cover on the outer side portion of the U-shape. It is good also as a structure formed in part just under a fitting joint position. As described above, by partially disposing the protrusion directly below the snap-fit coupling position, it is possible to reduce the assembly load between the case and the connector built-in cover, and to suppress the rattling of the snap-fit coupling claw. Can also be exhibited effectively.
According to a fourth aspect of the present invention, there is provided a box-like case having an opening provided on the front surface for accommodating a printed circuit board on which an electronic component is mounted, and a connector coupled to the printed circuit board. A cover with a built-in connector for covering, and an annular packing that is inserted and arranged around the opening of the case and between the cover with a built-in connector, and the case and the connector built-in cover are fixed by snap-fit coupling. An annular structure having a cross-sectional shape protruding from either the periphery of the opening of the case or the cover with a built-in connector in a fixing direction by the snap-fit coupling perpendicular to the front surface of the case. And a cross-sectional shape that fits into the convex portion is recessed around the opening of the case or the other side of the connector built-in cover. An annular concave portion is formed, and the packing has a U-shaped cross section, and a protrusion is located on the outer side portion of the U-shaped packing that is close to the snap-fit connection. The U-shaped packing covers the periphery of the tip of the convex portion, and the U-shape is formed between the tip surface of the convex portion and the bottom surface of the concave portion. It is characterized in that a cylindrical packing is inserted and arranged.
When it is not necessary to multiplex the sealing function for waterproofing, as described above, the projection and the side of the U-shaped packing that is close to the snap-fit coupling are arranged on the outer side of the case and the connector built-in cover. It is good also as a structure formed partially just under a snap fit coupling position. In this way, by partially arranging the protrusions directly below the snap-fit coupling position, it is possible to reduce the assembly load between the case and the connector built-in cover, and to suppress the rattling of the snap-fit coupling claw. It can be exhibited effectively.
In this case, for the reason described above, as described in claim 5 , the thickness of the bottom portion of the U-shaped packing that protrudes round is set to be thicker than the thickness of the U-shaped side portion. It is preferable.

  As described above, the casing structure of the electronic device is a casing structure of an electronic device having a waterproof packing and in which the case and the connector built-in cover are snap-fit coupled. As a result, it is possible to provide a housing structure for an electronic device that can be easily assembled and ensure sufficient waterproofness.

Therefore, the housing structure of the electronic device is suitable for use in an ECU of a vehicle as described in claim 6 .

  An ECU of a vehicle is required to be easily assembled and waterproof. On the other hand, a large rigidity is required because a large vibration is applied from the vehicle. Even with respect to such an ECU, by using the casing structure, an ECU having high rigidity and excellent assemblability can be obtained.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments relating to a housing structure of an electronic device according to the present invention will be described below with reference to the drawings.

1 and 2, but not in the present invention showing a housing structure of the electronic device 100 based. FIG. 1A is a top view of the appearance of the electronic device 100, and FIG. 1B is a side view of the appearance of the electronic device 100. FIG. 2 is an enlarged cross-sectional view of the portion indicated by the alternate long and short dash line B in FIG. 1, schematically showing a housing structure for coupling and waterproofing of the case 40 and the connector built-in cover 50 in the electronic device 100. It is.

  An electronic device 100 shown in FIGS. 1A and 1B and FIG. 2 is an electronic device used as an ECU (Electric Control Unit) of a vehicle.

  The electronic device 100 covers the box-shaped case 40 provided with an opening on the front surface that accommodates the printed circuit board 70 on which electronic components are mounted, and the opening of the case 40 containing a connector coupled to the printed circuit board 70. A connector built-in cover 50 and an annular packing 60 that is inserted and arranged between the opening of the case 40 and between the connector built-in cover 50 are provided. The case 40 and the connector built-in cover 50 are fixed by snap-fit coupling via a claw F40 provided on the case 40 side and a protrusion F50 provided on the connector built-in cover 50 side.

  As shown in FIG. 2, the packing 60 of the electronic device 100 has a circular cross-sectional shape. In addition, an annular convex portion (rib) whose cross-sectional shape protrudes around the opening of one case 40 in the fixing direction by snap-fit coupling indicated by a white arrow in FIG. 2 perpendicular to the front surface of the case 40. 41 is formed, and the other connector built-in cover 50 is formed with an annular concave portion 51 having a recessed cross-sectional shape that fits into the convex portion 41. And the packing 60 is inserted and arranged between the front end surface 41a of the convex portion 41 and the bottom surface 51a of the concave portion 51, and the inside of the electronic device 100 is waterproofly sealed.

  In general, when using a snap-fit coupling consisting of a combination of elastic claws and projections, the claws provided on one side are securely fitted to the other projections when assembling two objects to be fastened. Therefore, it is necessary to set a gap in the fixing direction by snap-fit coupling. The gap between the objects to be fastened in the fixing direction of the snap-fit connection usually remains after the two objects to be fastened by the snap-fit connection. For this reason, in the case structure of the electronic device 90 in which the case 10 and the connector built-in cover 20 shown in FIG. 9 are fixed by snap-fit coupling, the case 10 and the connector built-in cover 20 are rattled, and the snap-fit coupling is performed. It is easy to cause fatigue damage and impact noise.

  On the other hand, in the case structure of the electronic device 100 shown in FIG. 2, the convex portion 41 that fits between the case 40 and the connector built-in cover 50 to be fastened together in the fixing direction of the snap-fit connection indicated by the white arrow. A packing 60 is inserted and disposed between the front end surface 41 a and the bottom surface 51 a of the concave portion 51. The packing 60 is compressed in the fixing direction indicated by the white arrow in a state where the case 40 and the connector built-in cover 50 are snap-fit coupled. For this reason, even when the gap is set in the fixing direction in order to securely fit the claw F40 and the protrusion F50 provided to each other when the case 40 and the connector built-in cover 50 are assembled, the convex portion 41 is provided. The backlash between the case 40 and the connector built-in cover 50 can be suppressed by the repulsive force of the compressed packing 60 inserted between the front end surface 41a and the bottom surface 51a of the concave portion 51. Therefore, even when an external force or vibration is applied to the electronic device 100, it is possible to suppress the occurrence of fatigue failure and impact sound at the snap-fit joint portion. Needless to say, the packing 60 also ensures waterproofness inside the electronic device 100.

  As described above, the casing structure of the electronic device 100 shown in FIG. 2 is the casing structure of the electronic device having the waterproof packing 60 and the case 40 and the connector built-in cover 50 being snap-fit coupled. An electronic device housing structure that suppresses rattling of the case 40 and the connector built-in cover 50, suppresses fatigue breakage of the snap-fit joint portion, and can be easily assembled and ensure sufficient waterproofness. It has become.

  2, a convex portion (rib) 41 is formed around the opening of the case 40, and a concave portion 51 is formed in the connector built-in cover 50. Is inserted and disposed between the front end surface 41 a of the convex portion 41 and the bottom surface 51 a of the concave portion 51. However, the relationship of the above arrangement may be reversed including the examples shown below. That is, a concave portion is formed around the opening of the case, a convex portion (rib) is formed on the connector built-in cover, and the packing is inserted and disposed between the bottom surface of the concave portion and the front end surface of the convex portion. You may do it. Moreover, the cross-sectional shape of the packing inserted and disposed between the front end surface of the convex portion and the bottom surface of the concave portion is not limited to a circular shape, and may be an oval shape or a quadrangular shape. Further, as shown below, a packing having a U-shaped cross section may be used. In addition, when the cross-sectional shape of the packing is circular, oval, or quadrangular, the structure of the casing is as much as there is no U-shaped measuring part, compared to the case where a U-shaped packing having the following cross-sectional shape is used. Can be made thinner.

FIG. 3 is also a diagram showing an example of a housing structure of a base electronic device that is not the present invention. FIG. 3A is a view for coupling and waterproofing the case 42 and the connector built-in cover 52 in the electronic device 110. FIG. 3B is a sectional view schematically showing the housing structure, and FIG. 3B is an enlarged sectional view of the packing 62.

  As shown in FIG. 3, in the housing structure of the electronic device 110, a packing 62 having a U-shaped cross section is used. As for convex part (rib) 43 in case 42 of electronic device 110, the circumference of a tip is thinner than the base part, and as shown in Drawing 3 (a), the circumference of the tip of convex part 43 is U-shaped. The packing 62 is covered.

  Also in the case structure of the electronic device 110 shown in FIG. 3, an annular convex portion (rib) whose cross-sectional shape protrudes around the opening of one case 42 in the fixing direction by the snap-fit coupling indicated by the white arrow. ) 43 is formed, and the other connector built-in cover 52 is formed with an annular concave portion 53 having a recessed cross-sectional shape that fits into the convex portion 43. The packing 62 is inserted and disposed between the front end surface 43a of the convex portion 43 and the bottom surface 53a of the concave portion 53, and the inside of the electronic device 110 is waterproofly sealed. Therefore, in the case structure of the electronic device 110 shown in FIG. 3, as in the case structure of the electronic device 100 shown in FIGS. 1 and 2, even when an external force or vibration is applied to the electronic device 110, It is possible to suppress the occurrence of fatigue failure and impact sound at the snap-fit joint.

  On the other hand, according to the housing structure of the electronic device 110, as shown in FIG. 3A, the tip 42 of the convex portion 43 of the case 42 is covered with a packing 62 having a U-shaped cross section so that the case 42 is covered. The case 42 and the connector built-in cover 52 can be assembled in a state in which the packing 62 is disposed in advance around the opening, and can be fixed by snap-fit coupling via the claw F42 and the protrusion F52. For this reason, as compared with the housing structure of the electronic device 100 shown in FIGS. 1 and 2, the packing 62 can be easily assembled and the packing 62 can be prevented from being bent or misplaced. Assembly can be realized.

As shown in FIG. 3B, the packing 62 in the casing structure of the electronic device 110 is set such that the thickness dt of the U-shaped bottom is thicker than the thickness ds1, ds2 of the U-shaped measuring unit. It is preferable that According to this, at the bottom of the thick U-shaped packing 62 located between the front end surface 43a of the convex portion 43 of the case 42 and the bottom surface 53a of the concave portion 53 of the connector built-in cover 52, The space between the connector built-in covers 52 can be reliably waterproofed, and rattling between the case 42 and the connector built-in cover 52 in the fixing direction due to the snap-fit connection can be reliably suppressed. The thickness of the side portion of the U-shaped in the packing 62 ds1, ds2, in a state of covering the tip around the convex portion 43 of the case 42, the thickness is approximately in contact to the side wall of the concave portion 53 of the connector internal cover 52 It is preferable to set this value. As a result, when an external force is applied to the connector built-in cover 52 or the case 42 such as when the harness is attached / detached, the snap fit coupling portion can be prevented from being deformed by being restrained by the close contact portion.

4 to 6 are diagrams showing examples of the housing structure of the electronic device according to the present invention , and FIG. 4 is a top view of the appearance of each component shown by disassembling the electronic device 111. FIG. FIG. 5 is a cross-sectional view of a portion indicated by a one-dot chain line CC in FIG. 4. 6A is a cross-sectional view schematically showing a housing structure for coupling and waterproofing of the case 42 and the connector built-in cover 52 in the electronic device 111, and FIG. 6B is a packing 63. FIG. In the case structure of the electronic device 111 shown in FIG. 6A, the same reference numerals are given to the same parts as those of the case structure of the electronic device 110 shown in FIG.

The housing structure of the electronic device 111 shown in FIGS. 4 to 6 is different from the housing structure of the electronic device 110 shown in FIG. 3 only in the packing 63 used. The packing 63 used in the electronic device 111 has a U-shaped cross section like the packing 62 used in the electronic device 110, but as shown in FIGS. 6 (a) and 6 (b), the outer side portion of the U-shaped packing 63 wrapped around the tip of the convex portion 43 formed on the annular casing 42, the projections 63a~63c are formed.

In housing structure of the electronic device 111 shown in FIGS. 4 to 6, by forming a protrusion 63a~63c outside side portion of the U-shaped packing 63 as described above, cases 42 and the connector internal cover 52 snap fit connection state, not only the bottom of the U-shaped positioned between the bottom surface 53a of the distal end surface 43a and the concave portion 53 of the packing 63 is convex portion 43, the protrusion 63a formed on the outer side portion ˜63c can be set so as to be compressed. Thereby, not only the fixing direction of the snap fit connection but also the hooking direction of the nail F42 of the snap fit connection shown by the black arrow in FIG. A repulsive force can be generated to push up the hook portion of the claw F42. For this reason, the play in the hooking direction of the claw F42 can also be suppressed. For example, the deformation of the case 42 and the connector built-in cover 52 due to external force or environmental load causes the claw F42 of the snap-fit coupling portion to become shallower and the claw F42. Can be prevented from coming off easily.

In the housing structure of the electronic device 111 shown in FIGS. 4 to 6, the protrusions 63 a to 63 c of the packing 63 are U-shaped packing 63 that covers the periphery of the tip of the convex portion 43 formed in an annular shape of the case 42. along the outer side portion of, and is formed annularly. Accordingly, the protrusions 63a to 63c can be provided with a sealing function for waterproofing as well as suppressing the rattling of the claw F42 by the protrusions 63a to 63c. For this reason, the sealing function can be multiplexed with the bottom of the U-shaped packing 63 located between the tip surface 43a of the convex portion 43 and the bottom surface 53a of the concave portion 53 and the projections 63a to 63c. Reliability for waterproofing can be further increased.

  FIG. 7 is a diagram illustrating another example of the housing structure, and is a top view of the external appearance of each constituent element in which the electronic device 112 is disassembled. In the electronic device 112 shown in FIG. 7, the same parts as those of the electronic device 111 shown in FIG.

The electronic device 112 shown in FIG. 7 differs from the electronic device 111 shown in FIG. 4 only in the packing 64 used. Unlike the electronic device 111 shown in FIG. 4, the electronic device 112 shown in FIG. 7 is an electronic device that does not require multiplexing of a sealing function for waterproofing. The packing 64 of the electronic device 112 is also U-shaped in cross section like the packing 63 of the electronic device 111. However, as can be seen by comparing FIGS. 7 and 4, the packing 64 of FIG. , just below the snap-fit coupling position of the case 42 and the connector internal cover 52 on the side portion of the outer U-shaped, and has a partially formed configuration. As described above, by partially disposing the protrusion 64a directly below the snap-fit coupling position, it is possible to reduce the assembly load between the case 42 and the connector built-in cover 52, and to the direction in which the snap-fit coupling claw F42 is engaged. Suppression of backlash can also be exhibited effectively.

  As described above, the casing structure of the electronic devices 100 and 110 to 112 illustrated in FIGS. 1 to 7 includes the packings 60 and 62 to 64 for waterproofing, and the cases 40 and 42 and the connector built-in cover 50. , 52 is a housing structure of an electronic device to which a snap-fit connection is made, which prevents rattling between the cases 40, 42 and the connector built-in covers 50, 52, suppresses fatigue breakage of the snap-fit connection portion, and is assembled. Therefore, the housing structure of the electronic device can be secured easily and sufficiently waterproof.

  Therefore, the housing structure of the electronic devices 100 and 110 to 112 described above is suitable for use in an ECU of a vehicle.

  An ECU of a vehicle is required to be easily assembled and waterproof. On the other hand, a large rigidity is required because a large vibration is applied from the vehicle. Even with respect to such an ECU, by using the casing structure of the electronic devices 100 and 110 to 112 described above, an ECU having high rigidity and excellent assemblability can be obtained.

2A and 2B are views showing a housing structure of the electronic device 100 that is not the present invention, and FIG. 2A is a top view of the appearance of the electronic device 100, and FIG. 2B is a side view of the appearance of the electronic device 100; is there. FIG. 2 is an enlarged cross-sectional view of a portion indicated by a one-dot chain line B in FIG. 1, schematically showing a housing structure for coupling and waterproofing of a case 40 and a connector built-in cover 50 in the electronic device 100. FIG. 5 is a diagram illustrating an example of a housing structure of a base electronic device that is not the present invention , and FIG. 5A schematically illustrates a housing structure for coupling and waterproofing of a case and a connector built-in cover 52 in the electronic device 110; FIG. 6B is an enlarged cross-sectional view of the packing 62. It is a figure which shows the example of the housing structure of the electronic device which concerns on this invention, and is an upper surface figure of the external appearance of each component which decomposed | disassembled and showed the electronic device 111. It is sectional drawing of the part shown with the dashed-dotted line CC in FIG. (A) is a sectional view schematically showing a housing structure for coupling and waterproofing of the case 42 and the connector built-in cover 52 in the electronic device 111, and (b) is an enlarged sectional view of the packing 63. . It is a figure which shows the example of another housing structure, and is an upper surface figure of the external appearance of each component which decomposed | disassembled and showed the electronic apparatus 112. 2A and 2B are views showing a conventional ECU 90 in which a connector built-in cover and snap-fit coupling are used, in which FIG. 1A is a top view of the appearance of the ECU 90, and FIG. 2B is a side view of the appearance of the ECU 90. FIG. 9 is an enlarged cross-sectional view of a portion indicated by a one-dot chain line A in FIG. 8, schematically showing a housing structure for coupling and waterproofing of a case 10 and a connector built-in cover 20 in an ECU 90.

Explanation of symbols

100, 110-112 Electronic device 40, 42 Case 41, 43 Convex part (rib)
41a, 43a Front end surface F40, F42 Claw 50, 52 Connector built-in cover 51, 53 Recessed portion 51a, 53a Bottom surface F50, F52 Protrusion 60, 62-64 Packing 63a-63c, 64a Protrusion 70 Printed circuit board

Claims (6)

A box-like case provided with an opening on the front surface that accommodates a printed circuit board on which electronic components are mounted;
A connector built-in cover that incorporates a connector coupled to the printed circuit board and covers the opening of the case;
It has an annular packing inserted and arranged between the periphery of the opening of the case and the connector built-in cover,
A housing structure of an electronic device in which the case and the connector built-in cover are fixed by snap-fit coupling,
In the fixing direction by the snap-fit coupling perpendicular to the front surface of the case,
Around the opening of the case or the connector built-in cover, an annular convex portion with a cross-sectional shape protruding is formed,
Around the opening of the case or the other side of the connector built-in cover, an annular concave portion having a recessed cross-sectional shape fitted to the convex portion is formed,
The snap-fit coupling is arranged on the outer periphery of the annular concave portion,
The packing has a U-shaped cross-section, and the bottom of the U-shaped round protruding bottom is set to be thicker than the thickness of the U-shaped side,
Protrusions set thinner than the thickness of the bottom part that protrudes roundly are formed on both sides of the outer side part, which is the side close to the snap-fit coupling of the U-shaped packing,
The U-shaped packing covers the periphery of the tip of the convex part, and the bottom part of the packing is inserted and arranged between the tip surface of the convex part and the bottom surface of the concave part,
A casing structure for an electronic device, wherein the case and the connector built-in cover are fixed by the snap-fit connection, whereby a round protruding bottom portion of the packing is crushed and a waterproof seal is provided between the case and the connector built-in cover. The housing structure of the electronic device according to claim 1, wherein the protrusion is formed in an annular shape along the outer side portion . The case structure of the electronic device according to claim 1 , wherein the protrusion is partially formed immediately below a snap fit coupling position of the case and the connector built-in cover on the outer side portion . A box-like case provided with an opening on the front surface that accommodates a printed circuit board on which electronic components are mounted;
A connector built-in cover that incorporates a connector coupled to the printed circuit board and covers the opening of the case;
It has an annular packing inserted and arranged between the periphery of the opening of the case and the connector built-in cover,
A housing structure of an electronic device in which the case and the connector built-in cover are fixed by snap-fit coupling,
In the fixing direction by the snap-fit coupling perpendicular to the front surface of the case,
Around the opening of the case or the connector built-in cover, an annular convex portion with a cross-sectional shape protruding is formed,
Around the opening of the case or the other side of the connector built-in cover, an annular concave portion having a recessed cross-sectional shape fitted to the convex portion is formed,
The packing has a U-shaped cross-section, and a protrusion is partially formed on the outer side of the U-shaped packing that is close to the snap-fit connection, directly below the snap-fit connection position. Become
The U-shaped packing covers the periphery of the tip of the convex portion, and the U-shaped packing is inserted and disposed between the tip surface of the convex portion and the bottom surface of the concave portion. the housing structure as to electronic devices. The casing structure of the electronic device according to claim 4 , wherein a thickness of a bottom portion of the U-shaped packing protruding round is set to be thicker than a thickness of the U-shaped side portion . The case structure of an electronic device according to any one of claims 1 to 5, wherein the case structure of the electronic device is used in an ECU of a vehicle .

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