Electronic device including printed circuit board, connector and casing

An electronic device includes a printed circuit board, a connector mounted on the printed circuit board, a casing, and a sealing member. The casing houses the printed circuit board and a part of the connector in such a manner that the other part of the connector protrudes to an outside of the casing. The casing has a casing-side recess portion and a casing-side protruding portion that are connected each other to have a loop shape. The housing has a connector-side protruding portion and a connector-side recess portion that are connected to each other to have a loop shape. The connector-side protruding portion is fitted into the casing-side recess portion through the sealing member and the casing-side protruding portion is fitted into the connector-side recess portion through the sealing member.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is based on and claims priority to Japanese Patent Application No. 2007-234551 filed on Sep. 10, 2007, the contents of which are incorporated in their entirety herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electronic device that includes a printed circuit board, a connector mounted on the printed circuit board, and a casing for housing the printed circuit board and a part of the connector.

2. Description of the Related Art

According to the prior art, an electronic device includes a printed circuit board, a connector mounted on the printed circuit board, and a casing for housing the printed circuit.

For example, in each electronic control device disclosed in U.S. Pat. No. 6,707,678 (corresponding to JP-A-2001-85858 and JP-A-2001-85866), a casing includes a casing body and a cover. The casing body has an opening portion on an upper surface portion and houses an electronic circuit unit therein. The cover is disposed to close the opening portion of the casing body. The casing body has a connector opening at a sidewall thereof. The connector opening communicates with the opening portion. A part of the connector protrudes from the connector opening to an outside of the casing in a state where the printed circuit board is housed in the casing. A sealing member is disposed between an open edge portion of the casing body and a flange portion of the cover and between an inner surface of the connector opening and an outer surface of the connector, respectively.

In one electronic control device disclosed in U.S. Pat. No. 6,707,678, the connector has a groove at an upper surface thereof and a protruding portion at a lower surface thereof. However, side surfaces of the connector are substantially flat. In addition, side portions of the connector opening that face the side surfaces of the connector are also substantially flat. Thus, in a case where a sealing part has a substantially constant width, leak paths at a part of the sealing part located between the side surfaces of the connector and the side portions of the connector opening are shorter than a leak path at the other part of the sealing part. Furthermore, contact areas between the sealing member and the side surfaces of the connector and the constant areas between the sealing member and the side portions of the connector opening are reduced compared with the other portion. Thus, it is difficult to improve a sealing property, i.e., waterproof property of the casing while reducing a dimension of the electronic control device in a direction where the connector is fitted with an external connector.

In another electronic control device disclosed in U.S. Pat. No. 6,707,678, one of the side surfaces of the connector and the side portions of the connector opening are substantially flat and the other one have protruding portions. The protruding portions are disposed to provide predetermined clearances between the side surfaces of the connector and the side portions of the connector opening. Thus, even though the protruding portions are disposed, the lengths of the leak paths are not increased and the constant areas with the sealing member change little. In addition, in a case where the protruding portion comes in contact with the flat portion only one side due to a tolerance or a displacement, the clearance on the other side may become large. Thereby, the sealing member may run short and the sealing property may be reduced.

SUMMARY OF THE INVENTION

In view of the foregoing problems, it is an object of the present invention to provide an electronic device that can improve a sealing property.

According to an aspect of the invention, an electronic device includes a printed circuit board, a connector, a casing, and a sealing member. The printed circuit board has a first surface and a second surface and includes a plurality of lands. The connector is disposed on the first surface of the printed circuit board and includes a housing and a plurality of terminals. The plurality of terminals is arranged in the housing and is electrically coupled with the plurality of lands respectively for electrically coupling the printed circuit board and an external connector. The casing includes a first case disposed on the first-surface side of the printed circuit board and second case disposed on the second-surface side of the printed circuit board. The casing has a connector opening defined by an open edge portion of the first case and an open edge portion of the second case. The casing houses the printed circuit board and a part of the connector in such a manner that the other part of the connector protrudes from the connector opening to an outside of the casing. The sealing member is disposed between a peripheral edge portion of the first case and an peripheral edge portion of the second case and between the open edge portions of the casing and a surface of the housing so that an inside of the casing is waterproof. The casing has a sealing part coming in contact with the sealing member and the sealing part of the casing includes a casing-side recess portion and a casing-side protruding portion. The casing-side recess portion extends from one longitudinal end to the other longitudinal end of the open edge portion of one of the cases. The casing-side protruding portion extends from one longitudinal end to the other longitudinal end of the open edge portion of the other case. The housing has a sealing part coming in contact with the sealing member and extending on the surface of the housing so as to have a loop shape. The sealing part of the housing includes a connector-side protruding portion and a connector-side recess portion that are connected to each other. The connector-side protruding portion is fitted into the casing-side recess portion through the sealing member. The casing-side protruding portion is fitted into the connector-side recess portion through the sealing member.

In the present electronic device, a sealing property can be improved without increasing a dimension of the electronic device in a direction where the connector is fitted with the external connector.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

An electronic control device100according to an exemplary embodiment of the invention will be described with reference toFIGS. 1-14.

The electronic control device100has a waterproof structure and can be suitably used as an electronic control unit disposed outside of a vehicle compartment. For example, the electronic control device100can be used as an engine control unit (engine ECU) disposed in an engine room.

As illustrated inFIGS. 1-3, the electronic control device includes a casing10, a printed circuit board40housed in the casing10, and a connector50mounted on the printed circuit board40, and a sealing member60for waterproofing the casing10. The connector50is housed in the casing10in such a manner that a part of the connector50protrudes to an outside of the casing10.

The casing10includes an upper case20and a lower case30. The connector50is mounted on an upper surface of the printed circuit board40. The upper case20is arranged on the upper-surface side of the printed circuit board40and the lower case30is arranged on a lower-surface side of the printed circuit board40.

As illustrated inFIG. 4, the upper case20has an opening portion21that opens toward the lower case30. The upper case20is formed by aluminum die casting, pressing, or resin molding, for example. The upper case20has a bottom surface22that has an approximately rectangular shape. At three side portions of the approximately rectangular shape, a flange portion23is disposed. The flange portion23faces a fixing portion of the lower case30through a sidewall of the upper case20. The other one side portion of the approximately rectangular shape, an open edge portion24is disposed. The open edge portion24has an approximately trapezoid shape. The open edge portion24is coupled with the flange portion23at two longitudinal ends thereof. The upper case20has an approximately dustpan-shape, in which an opposite surface of the bottom surface22and one side of the sidewall are open and the flange portion23and the open edge portion24surround the bottom surface22and the sidewall. A sealing part that comes in contact with the sealing member60is provided at the flange portion23, i.e., a peripheral edge portion of the upper case20and the open edge portion24so as to have a loop shape surrounding the bottom surface22and the opening portion21.

For example, the sealing part of the upper case20includes a casing-side protruding portion25. The casing-side protruding portion25includes a first protruding part25aand a second protruding part25b. The first protruding part25aprotrudes from a surface of the flange portion23toward the lower case30and extends from one longitudinal end to the other longitudinal end of the flange portion23. The second protruding part25bprotrudes from a surface of the open edge portion24toward the lower case30and extends from one longitudinal end to the other longitudinal end of the open edge portion24. The first protruding part25aand the second protruding part25bare connected to each other at the longitudinal ends of the flange portion23so as to have the loop shape.

At the open edge portion24, a fitting projection26is disposed between the bottom surface22and the second protruding part25b. The fitting projection26extends from the one longitudinal end to the other longitudinal end of the open edge portion24and is arranged approximately parallel to the second protruding part25b. A protruding height of the fitting projection26from the surface of the open edge portion24is larger than a protruding height of the second protruding part25bfrom the surface of the open edge portion24.

As illustrated inFIGS. 1 and 2, the upper case20has a plurality of attaching holes27for attaching the electronic control device100to the vehicle by using brackets (not shown). In addition, as illustrated inFIG. 4, the upper case20has a plurality of screw holes28for fixing the upper case20and the lower case30by using screws70.

As illustrated inFIG. 5, the lower case30has an opening portion31that opens toward the upper case20. The lower case30is formed by aluminum die casting, pressing, or resin molding, for example. The lower case30has a bottom surface32that has an approximately rectangular shape. At three side portions of the approximately rectangular shape, a flange portion33is disposed. The flange portion33faces a fixing portion of the upper case20, i.e., the flange portion23of the upper case20, through a sidewall of the lower case30. The other one side portion of the rectangular shape, an open edge portion34is disposed. The open edge portion34has an approximately trapezoid shape. The open edge portion34is coupled with the flange portion33at two end portions thereof. That is, the lower case30also has an approximately dustpan-shape, in which an opposite surface of the bottom surface32and one side of the sidewall are open and the flange portion33and the open edge portion34surround the bottom surface32and the sidewall. A sealing part that comes in contact with the sealing member60is provided at the flange portion33, i.e., a peripheral edge portion of the lower case30and the open edge portion34so as to have a loop shape surrounding the bottom surface32and the opening portion31.

For example, the sealing part of the lower case30includes a casing-side recess portion35. The casing-side recess portion35includes a first recess part35aand a second recess part35b. The first recess part35ais provided at a surface portion of the flange portion33so as to correspond the first protruding part25aof the upper case20. The first recess part35aextends from one longitudinal end to the other longitudinal end of the flange portion33. The second recess part35bis provided at a surface portion of the open edge portion34. The second recess part35bextends from one longitudinal end to the other longitudinal end of the open edge portion34. The first recess part35aand the second recess part35bare connected to each other at the longitudinal ends of the flange portion33so as to have the loop shape. A width of the first recess part35ais larger than a width of a width of the first protruding part25aof the upper case20so that the first protruding part25acan be inserted into the first recess part35ain a state where the sealing member60is filled in the first recess part35a.

Furthermore, the lower case30has fitting grooves36at connecting parts of the open edge portion34with the flange portion33. For example, the fitting grooves36are provided at a sidewall of the open edge portion34.

As illustrated inFIGS. 5-7, at the longitudinal ends of the open edge portion34of the lower case30, nesting parts37are disposed. The nesting parts37protrude toward the upper case20. Sidewalls of the nesting parts37on the bottom-surface side become sidewalls of the fitting grooves36.

The lower case30has a plurality of screw holes38for fixing the upper case20and the lower case30by using the screws70.

The printed circuit board40has wirings and via holes for coupling the wirings. The wirings include lands as electrodes. On the upper surface of the printed circuit board40, a plurality of electronic elements41is mounted. The electronic elements41include a microcomputer, a power transistor, a resistor, and a capacitor, for example. The connector50for coupling the printed circuit board40to an external device is mounted on the printed circuit board40as one of the electronic elements41.

The printed circuit board40may be made of thermoplastic resin, thermosetting resin, ceramics, or a complex of glass (e.g., glass fabric) and resin, for example. The number of layer of the printed circuit board40is not limited. The printed circuit board40has a plurality of through holes42that extends from the upper surface to the lower surface. The connector50has a plurality of terminals52. An end portion of each terminal52is inserted into corresponding through hole42. A coupling structure of the terminals52with the printed circuit board40have a part in common with a coupling structure disclosed in JP-A-2007-148613 (corresponding to U.S. patent application Ser. No. 11/979968) by the inventor. Thus, a detail description of the coupling structure is omitted.

The connector50has a housing51and the terminals52arranged in the housing51. The housing51is made of an insulating material. The terminals52are made of a conductive material. The end portions of the terminals52extend from the housing51and are coupled with the lands (not shown) of the printed circuit board40through a solder.

The terminals52include first terminals52a, second terminals52b, and at least one third terminal52c, e.g., three third terminals52c. The first terminals52aand the second terminals52have an electric coupling function between the printed circuit board40and the connector50. One end portions of the first terminals52aand the second terminals52bextending from the housing51are electrically and mechanically coupled with the lands of the printed circuit board40through the solder. The other end portions of the first terminals52aand the second terminals52bextending from the housing51are electrically coupled with the external connector. The third terminals52cdo not have an electric coupling function between the connector50and the printed circuit board40. The third terminals52care provided for improving a connectivity of the connector50with the printed circuit board40.

As illustrated inFIG. 1,FIG. 3, andFIGS. 6-9, the housing51has a sealing part coming in contact with the sealing member60and extending on a surface of the housing so as to have a loop shape. For example, the sealing part of the housing51includes a connector-side recess portion53and a connector-side protruding portion54that are connected to each other. The connector-side recess portion53corresponds to the second protruding part25bof the upper case20. The connector-side protruding portion54corresponds to the second recess part35bof the lower case30. At the connecting parts of the connector-side recess portion53with the connector-side protruding portion54, a center portion of the connector-side recess portion53and a center portion of the connector-side protruding portion54are aligned. A width of the connector-side recess portion53is larger than a width of the second protruding part25bof the upper case20so that the second protruding part25bcan be inserted into the connector-side recess portion53in a state where the sealing member60is filled in the connector-side recess portion53. A width of the connector-side protruding portion54is less than a width of the second recess part35bof the lower case30so that the connector-side protruding portion54can be inserted into the second recess part35bin a state where the sealing member60is filled in the second recess part35b. The sealing part of the housing51has an approximately hexagonal contour. An upper surface portion and a lower surface portion of the sealing part oppose to each other and are approximately parallel to the upper surface of the printed circuit board. The connector-side recess portion53and the connector-side protruding portion54are connected to each other at two vertices of the approximately hexagonal contour. That is, the connector-side recess portion53is provided at the upper surface portion and two surface portions adjacent to the upper surface portion. The connector-side protruding portion54is provided at the lower surface portion and two surface portions adjacent to the lower surface portion.

The nesting parts37of the lower case30are locked into an inner wall of the connector-side recess portion53at the connecting parts of the connector-side recess portion53and the connector-side protruding portion54. Thereby, a length of a leak path can be increased and a sealing property of the electronic control device100can be improved.

On the upper surface of the housing51, a fitting groove55is provided to correspond to the fitting projection26provided at the open edge portion24of the upper case20. The fitting groove55is provided in a longitudinal direction of the housing51. The fitting groove55has a length substantially similar to the connector-side recess portion53and is arranged approximately parallel to the connector-side recess portion53. At the longitudinal ends of the housing51, fitting projections56are disposed to correspond to the fitting grooves36provided in the lower case30. Surface portions of the housing51at which the fitting groove55and the fitting projections56are provided have contours that are different from the approximately hexagonal contour of the sealing part. In addition, the housing51has a plurality of protruding portions58on an outer surface thereof so that the external connector can be fitted with the connector50.

The terminals52are arranged in the housing51in a zigzag manner in the longitudinal direction of the housing51. In addition, the terminals52are arranged in a plurality of rows in a direction perpendicular to the upper surface of the printed circuit board40, i.e., in a thickness direction of the printed circuit board40. For example, the plurality of rows is greater than or equal to three rows. As illustrated inFIG. 3, the terminals52extend from the housing51in such a manner a distance between a portion of the housing51where the external connector is fitted with and a portion of the housing51where each terminal52extends from increases toward an opposite side of the upper surface of the printed circuit board40. That is, a length of a portion of each terminal52embedded in the housing51increases upward. In the terminals52, the first terminals52aare signal terminals for transmitting signals. The second terminals52b, which are thicker than the first terminals52a, are power terminals for transmitting electricity from a power element. As illustrated inFIG. 9, the first terminals52aare arranged in six rows in the direction perpendicular to the upper surface of the printed circuit board40. The second terminals52bare arranged in three rows in the direction perpendicular to the upper surface of the printed circuit board40. The connector50has first terminal blocks57aand second terminal blocks57barranged in the longitudinal direction of the housing51. In the first terminal blocks57a, only the first terminals52aare arranged. In the second terminal blocks57b, only the second terminals52bare arranged. For example, in the longitudinal direction of the housing51, three first terminal blocks57aare arranged between two second terminal blocks57b. In addition, the connector50has a first connection port51aand a second connection port51bto be coupled with the external connector. In the first connection port51a, one of the first terminal blocks57aand one of the second terminal blocks57bare arranged. In the second connection port51b, two of the first terminal blocks57aand one of the second terminal blocks57bare arranged.

As illustrated inFIGS. 9-11, in the second terminal block57barranged adjacent to one longitudinal end of the housing51, each of the three rows has an end second terminal52bthat is closest to the one longitudinal end of the housing51among the second terminals52bin each row. Among the end second terminals52b, the end second terminal52barranged in the middle row (i.e., second row) in the thickness direction of printed circuit board40is closest to the one longitudinal end of the housing51and the end second terminal52barranged in the highest row (i.e., third row) is farthest from the one longitudinal end of the housing51.

The third terminals52care reinforcing terminals. Each third terminal52chas only one end portion that extends from the housing51and is coupled with the land of the printed circuit board40. For example, in the longitudinal direction of the housing51, two of the third terminals52care arranged outside of the second terminal blocks57brespectively, and one of third terminal52care arranged between the first connection port51aand the second connection port51b. Each terminal52(52a-52c) is a branch terminal that has an insertion section to be inserted into a through hole42provided in the printed circuit board40and a surface section to be disposed on the upper surface of the printed circuit board40.

The sealing member60is made of a material that can produce a sealing effect so that the space in the casing10becomes waterproof. For example, the sealing member60is made of a material that has adhesiveness and that can bond the upper case20and the lower case30, the upper case20and the housing51of the connector50, and the lower case30and the housing51of the connector50by curing. Alternatively, the sealing member60may be made of a material that has a low adhesiveness and a high repelling force (i.e., elasticity) so that clearances can be filled by the repelling force. Alternatively, the sealing member60may be made of a material that has a high adhesiveness and a high repelling force. For example, the sealing member60is made of a moisture-curing silicone adhesive having a viscosity in a range from about 150 Pa·s to about 200 Pa·s before curing.

An assembling process of the electronic control device100will now be described. At first, as illustrated inFIG. 12, the sealing member60is applied to the second recess part35bprovided at the open edge portion34of the lower case30. Next, as illustrated inFIG. 13, the fitting projections56of the housing51are fitted into the fitting grooves36of the lower case30. In addition, the connector-side protruding portion54is inserted into the second recess part35bof the lower case30so that the connector-side protruding portion54comes in contact with the sealing member60applied to the second recess part35b. Thereby, the printed circuit board40on which the electronic elements41including the connector50are mounted is disposed on the lower case30. InFIG. 13, the printed circuit board40is not illustrated. In the present state, the connector-side recess portion53communicates with the first recess part35aof the lower case30.

Thus, after the printed circuit board40is disposed on the lower case30, the sealing member60is applied to the connector-side recess portion53and the first recess part35aof the lower case30at a time, as illustrated inFIG. 14. Next, the fitting projection26of the upper case20is fitted into the fitting groove55provided at the housing51. In addition, the first protruding part25aand the second protruding part25bof the casing-side protruding portion25are inserted into the first recess part35aand the connector-side recess portion53, respectively, so that the casing-side protruding portion25comes in contact with the sealing member60. Thereby, the upper case20is disposed on the lower case30in such a manner that the opening portion31of the lower case30is covered by the upper case20. Furthermore, a connector opening of the casing10is defined by the open edge portion24of the upper case20and the open edge portion34of the lower case30, and the casing10houses the printed circuit board40and a part of the connector50in such a manner that the other part of the connector50protrudes from the connector opening to the outside of the casing10. Then, the screws70are inserted into the screw holes28and38and are fastened.

In the above-described process, the fitting projection26is fitted into the fitting groove55of the housing51before the second protruding part25bis inserted into connector-side recess portion53of the housing51because the protruding height of the fitting projection26is larger than the protruding height of the second protruding part25b.

As described above, the first protruding part25ais formed at the flange portion23of the upper case20and the first recess part35ais formed at the flange portion33of the lower case30. The flange portion23of the upper case20faces the flange portion33of the lower case30, and at least a part of the first protruding part25ais inserted into the sealing member60in the first recess part35a. In addition, the second protruding part25bis formed at the open edge portion24of the upper case20and the connector-side recess portion53is formed at the housing51of the connector50so that at least a part of the second protruding part25bis buried in the sealing member60in the connector-side recess portion53. Furthermore, the second recess part35bis formed at the open edge portion34of the lower case30and the connector-side protruding portion54is formed at the housing51of the connector50so that at least a part of the connector-side protruding portion54is buried in the sealing member60in the second recess part35b. Thereby, the space in the casing10is sealed to be airproof.

In the electronic control device100, at the surface portion of the housing51that faces the open edge portions24and34, the connector-side recess portion53and the connector-side protruding portion54are continuously formed to have the loop shape. In addition, in a state where the upper case20and the lower case30are assembled into the casing10, the second protruding part25band the second recess part35bare provided at the whole circumference of the open edge portions24and34so as to have a loop shape. Thus, the length of the leak path increases at the whole circumference of the sealing part on the surface portion of the housing51, and a contact area with the sealing member60increases. Thus, the sealing property of the electronic control device100can be improved without increasing a width of the sealing part. As a result, the sealing property of the electronic control device100can be improved without increasing a dimension of the electronic control device100in a direction where the connector50is fitted with the external connector (i.e., fitting direction).

Furthermore, the first protruding part25ais formed at the flange portion23of the upper case20in addition to the second protruding part25bformed at the open edge portion24. Thus, the casing-side protruding portion25including the first protruding part25aand the second protruding part25bhas the loop shape surrounding the bottom surface22. In a similar manner, the first recess part35ais formed at the flange portion33of the lower case30in addition to the second recess part35bformed at the open edge portion34. Thus, the casing-side recess portion35including the first recess part35aand the second recess part35bhas the loop shape surrounding the bottom surface32. Thereby, the sealing property of the electronic control device100can be further improved without increasing a dimension of the electronic control device100in a direction along the upper surface of the printed circuit board40.

In the present case, the casing-side protruding portion25is only disposed in the upper case20and the casing-side recess portion35is only disposed in the lower case30. Because both of the upper case20and the lower case30has only one of the casing-side protruding portion25and the lower case30, the upper case20and the lower case30can be formed by pressing at a low cost as well as aluminum die casting and resin molding.

In a case where the length of the leak path can be increased by extending the flange portions23and33toward the opening portions21and31, respectively, flat portions of the flange portions23and33may be used as at least a part of the sealing part on the flange portions23and33.

The lower case30disposed on the lower-surface side of the printed circuit board40has the casing-side recess portion35as the sealing part that comes in contact with the sealing member60. In addition, the connector-side protruding portion54is formed on the surface of the housing51so as to face the second recess part35bof the casing-side recess portion35formed at the open edge portion34. The width of the connector-side protruding portion54may be less than the width of the connector-side recess portion53. Thus, the length of the housing51in the fitting direction can be reduced. Furthermore, as illustrated inFIG. 1, the printed circuit board40can be disposed close to the portion of the housing51where the external connector is fitted with. That is, the dimension of the electronic control device100in the fitting direction can be reduced.

As illustrated inFIG. 3, the terminals52are arranged in the housing51in such a manner that the distance between the portion of the housing51where the external connector is fitted with and the portion of the housing51where each terminal52extends from increases toward an opposite side of the upper surface of the printed circuit board40. Thus, the thickness of the housing51in the fitting direction increases upward, that is, toward an opposite side of the upper surface of the printed circuit board40. In this way, in the housing51, the thickness at the portion where the connector-side recess portion53is formed is ensured. Thus, the connector-side recess portion53can be formed at the housing51without increasing the dimension of the electronic control device100in the fitting direction.

In addition, the fitting groove55is formed adjacent to the connector-side recess portion53of the housing51. Furthermore, the fitting projection26is formed adjacent to the second protruding part25bof the upper case20so as to correspond to the fitting groove55. Thus, by fitting the fitting projection26into the fitting groove55, a relative position of the connector50and the upper case20is determined. Thereby, a gouge of the connector50with respect to the casing10, that is, a displacement of the second protruding part25bin the connector-side recess portion53and a displacement of the connector-side protruding portion54in the second recess part35bcan be reduced in the fitting direction. In addition, the sealing member60is restricted from being pushed out of the connector-side recess portion53. Because a fitting part including the fitting groove55and the fitting projection26is formed adjacent to the sealing part, a stress generated at the connector50can be released to the casing10through the fitting part. Thereby, a stress applied to the sealing part is reduced and the sealing property can be improved. Furthermore, because a stress applied to coupling potions of the terminals52with lands also can be reduced, an electric connectivity of the terminals52with the lands can be improved.

In the present case, the fitting projection26extends in a direction approximately parallel to the extending direction of the second protruding part25b, as illustrated inFIG. 4. In addition, the fitting groove55extends in a direction approximately parallel to the extending direction of the connector-side recess portion53. Thus, in the fitting direction, the displacement of the second protruding part25bin the connector-side recess portion53and the displacement of the connector-side protruding portion54in the second recess part35bcan be effectively reduced while restricting an increase of the dimension of the electronic control device100due to providing the fitting part.

Furthermore, the fitting projections56are disposed at the both longitudinal end portions of the housing51, and the fitting grooves36are disposed at the open edge portion34of the lower case30so as to correspond to the fitting projections56. Thus, a fitting part including the fitting projections56and the fitting grooves36effectively restrict the displacement of the second protruding part25bin the connector-side recess portion53and the displacement of the connector-side protruding portion54in the second recess part35b. Especially, because the fitting part is located at the both longitudinal end portions of the housing51, the fitting part can restrict a gouge of the housing51in the longitudinal direction of the housing51.

The fitting projection26and the fitting groove55are configured in such a manner that the fitting projection26is inserted into the fitting groove55before the second protruding part25bis inserted into the connector-side recess portion53when the casing10is assembled to house the printed circuit board40and the connector50. Thus, the second protruding part25bis inserted into the connector-side recess portion53in a state where the relative position of the casing10and the connector50is determined by the fitting part including the fitting projection26and the fitting groove55. Thus, when the second protruding part25bis inserted into the connector-side recess portion53, the sealing member60is reduced from being pushed out of connector-side recess portion53. Thereby, a reduction of the sealing property can be effectively restricted. In addition, the fitting grooves36and the fitting projections56are configured in such a manner that the fitting projections56are inserted into the fitting grooves36before the connector-side protruding portion54is inserted into the second recess part35b. The gouge of the connector50with respect to the casing10can be effectively restricted by reducing a tolerance of the fitting projection26and the fitting groove55and a tolerance of the fitting projections56and the fitting grooves36rather than reducing a tolerance of the second protruding part25band the connector-side recess portion53and a tolerance of the connector-side protruding portion54and the second recess part35b. Furthermore, when an insertion depth of the fitting projection26to the fitting groove55and an insertion depth of the fitting projections56to the fitting grooves36are larger than an insertion depth of the second protruding part25bto the connector-side recess portion53and an insertion depth of the connector-side protruding portion54to the second recess part35b, respectively, the gouge of the connector50with respect to the casing10can be effectively restricted.

The sealing part of the housing51has the approximately hexagonal contour and the upper surface portion and the lower surface portion of the sealing part are appropriately parallel to the upper surface of the printed circuit board40. In addition, the connector-side recess portion53and the connector-side protruding portion54are coupled each other at the two vertices of the approximately hexagonal contour. Thus, the length of the housing51in the longitudinal direction of the housing51can be reduced compared with a case where the sealing part of the housing51has a trapezoid contour. Furthermore, the housing51can be fitted with the lower case30and the upper case20can be fitted with the housing51without scraping away the sealing member60.

As illustrated inFIG. 11, the first terminals52aand the second terminals52bare arranged in the housing51in the zigzag manner in the longitudinal direction of the housing51. In addition, the first terminals52aand the second terminals52bare arranged in the plurality of rows greater than or equal to three rows in the thickness direction of the printed circuit board40at least at portions adjacent to the longitudinal ends of the housing51. In the second terminal block57barranged adjacent to the one longitudinal end of the housing51, each of the three rows has the end second terminal52bthat is closest to the one longitudinal end of the housing51among the second terminals52bin each row. Among the end second terminals52b, the end second terminal52barranged in the middle row in the thickness direction of the printed circuit board40is closest to the one longitudinal end of the housing51. That is, the second terminal52bthat is closest to the one longitudinal end of the housing51among the first terminals52aand the second terminals52bis arranged in the middle row. Thus, in the housing51in which the sealing part has the approximately hexagonal contour, the first terminals52aand the second terminals52bcan be arranged to portions close to the longitudinal ends of the housing51. Thereby, the length of the housing51in the longitudinal direction can be reduced.

Furthermore, in the second terminal block57barranged adjacent to the one longitudinal end of the housing51, the end second terminal52barranged in the highest row, that is, the end second terminals52bthat is closest to the upper surface portion of the housing51is farthest from the one longitudinal end of the housing51among the end second terminals52b. The upper case20has the casing-side protruding portion25and the housing51has the connector-side recess portion53at the upper surface portion. Because the end second terminal52barranged in the highest row is farthest from the one longitudinal end of the housing51, the end second terminal52bis difficult to interfere with a bottom surface53aof the connector-side recess portion53illustrated by the dashed line inFIG. 11. Thus, the length of the housing51in the longitudinal direction can be reduced. InFIG. 11, the dashed-dotted line illustrates a comparative example in which the end second terminal52bin the highest row is arranged closer to the one longitudinal end of the housing51. The dashed-two dotted line illustrates a base of the connector-side protruding portion54. Furthermore, a surface portion53bsurrounding the connector-side recess portion53and a tip54bof the connector-side protruding portion54are illustrated inFIG. 11.

Other Embodiments

In the above-described exemplary embodiment, each terminal52of the connector50is a T-shaped branch terminal including the insertion section and the surface section, as illustrated inFIG. 3. Alternatively, each terminal52may have one of the insertion section and the surface section. Alternatively, each terminal52may be a branch terminal having an inverted L-shape. Alternatively, a part of the terminals52may be the branch terminals.

In the above-described exemplary embodiment, the terminals52include the first terminals52a, the second terminals52b, and the third terminals52c, as an example. The type of the terminal52is not limited to the above-described example. For example, the terminals52may not include the third terminals52cas the reinforcing terminals. The number, the type, and the arrangement of the terminal block are not limited to the above-described example. Furthermore, the number of row and the arrangement of the terminals52in the housing51are not limited to the above-described example.

In the above-described exemplary embodiment, the electronic control device100is described as an example of an electronic device. However, the electronic device may be any waterproof electronic device in which the printed circuit board40is housed in the casing10including the upper case20and the lower case30and a part of the connector50mounted on the printed circuit board40protrudes from the connector opening to an outside of the casing10.

In the above-described exemplary embodiment, the fitting projection26is disposed at the upper case20and the fitting groove55is disposed at the housing51to configurate the fitting part. In addition, the fitting grooves36are disposed at the lower case30and the fitting projections56are disposed at the housing51to configurate another fitting part. Alternatively, the electronic control device100may have one of the fitting parts.

In the above-described exemplary embodiment, the open edge portion24of the upper case20is formed in the whole area of one side portion of the upper case20and the open edge portion34of the lower case30is formed in the whole area of one side portion of the lower case30. Alternatively, the open edge portion24may be formed at a part of the one side portion of the upper case20and the opening edge portion34may be formed at a part of the one side portion of the lower case30. The shapes of the connector opening and the open edge portions24and34are not limited to the above-described example.

In the above-described exemplary embodiment, the sealing part of the housing51has the approximately hexagonal contour, as an example. Alternatively, as illustrated inFIG. 15andFIG. 16, the sealing part of the housing51may have an approximately trapezoid contour including an upper base and a lower base. For example, the lower base is longer than the upper base. In the present case, the sealing part of the lower case30that faces the lower base of the sealing part of the housing51can be disposed on one plane. Thus, the lower case30can have a simple structure. In addition, when the sealing part of the housing51has the approximately trapezoid contour, the housing51can be fitted with the lower case30and the upper case20can be fitted with the housing51without scraping away the sealing member60in a manner similar to a case where the sealing part of the housing51has the approximately hexagonal contour.

In the above-described exemplary embodiment, the upper case20has the casing-side protruding portion25and the lower case30has the casing-side recess portion35. Alternatively, the upper case20may have a casing-side recess portion and the lower case30may have a casing-side protruding portion. In the present case, the connector-side protruding portion54and the connector-side recess portion53are formed on the surface of the housing51to correspond to the casing-side recess portion and the casing-side protruding portion, respectively.

In the above-described exemplary embodiment, the upper case20has the fitting projection26and the housing51has the fitting groove55corresponding to the fitting projection26, as an example. Alternatively, the upper case20may have a fitting groove and the housing51may have a fitting projection. Furthermore, in the above-described exemplary embodiment, the lower case30has the fitting grooves36and the housing51has the fitting projections56corresponding to the fitting grooves36, as an example. Alternatively, the lower case30may have a fitting projection and the housing51may have a fitting groove.

In the above-described exemplary embodiment, with respect to fitting portion of the housing51where the external connector is fitted with, the fitting part including the fitting projection26and the fitting groove55are farther away than the sealing part including the second protruding part25bof the upper case20and the connector-side recess portion53. Alternatively, the fitting part may be located between the fitting portion with the external connector and the sealing part. Alternatively, the lower case30may have a fitting projection extending in a direction approximately parallel to the sealing part and the housing51may have a fitting groove corresponding to the fitting projection of the lower case30.

In the above-described exemplary embodiment, at the connecting parts of the connector-side recess portion53and the connector-side protruding portion54, the center portion of the connector-side recess portion53and the center portion of the connector-side protruding portion54are aligned, as an example. Alternatively, the center portion of the connector-side recess portion53and the center portion of the connector-side protruding portion54may be out of alignment as long as the connector-side recess portion53and the connector-side protruding portion54are connected to each other.

In the above-described exemplary embodiment, the nesting parts37of the lower case30are locked into an inner wall of the connector-side recess portion53at the connecting parts of the connector-side recess portion53and the connector-side protruding portion54for increasing the length of the leak path by the nesting parts37and the connector-side protruding portion54. Alternatively, the lower case30may not have the nesting parts37. Alternatively, the housing51may have a nesting part adjacent to the connector-side recess portion53and the nesting part, the connector-side protruding portion54and the second protruding part25bof the upper case20may be inserted into the second recess part35bof the lower case30for increasing the length of the leak path. That is, the connector-side recess portion53, the connector-side protruding portion54, the second protruding part25band the second recess part35bmay be used as nesting parts for increasing the length of the leak path.