Electronic unit

Abstract

A technology capable of improving the waterproofness of an electronic unit is provided. The electronic unit comprises: a housing having an opening; a circuit substrate received in the housing through the opening; and a cover mounted on the opening, wherein at least one side wall of the housing is provided with a protrusion, the protrusion is provided to include a step that makes the opening side portion of the side wall protrude further outward than the inner side portion and extends along the periphery of the opening.

Description

Technical Field

[0001] The present disclosure relates to an electronic unit. Background Art

[0002] Patent Document 1 discloses a vehicle control device in which an electronic circuit board is housed in a case member and a cover member is attached. In Patent Document 1, a flange portion is provided around the cover member to implement a simple waterproof structure on the vehicle control device.

[0003] Prior art literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2019-71376

[0005] Patent Document 2: Japanese Patent Application Publication No. 2015-60708 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, in the technology described in Patent Document 1, there is a possibility that water flowing along the outer surface of the case member may intrude into the gap between the case member and the cover member.

[0008] Therefore, an object of the present invention is to provide a technology capable of improving the waterproof property of an electronic unit.

[0009] Technical solutions to solve problems

[0010] The electronic unit disclosed in the present invention comprises: a shell having an opening; a circuit substrate housed in the shell through the opening; and a cover mounted on the opening, wherein a protrusion is provided on at least one side wall of the shell, and the protrusion is provided to include a step that makes the opening side portion of the side wall protrude further outward than the inner side portion and extends around the opening.

[0011] Effects of the Invention

[0012] According to the present disclosure, it is possible to improve the waterproofness of the electronic unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a perspective view showing the electronic unit according to the embodiment.

[0014] Figure 2 It is a front view showing the electronic unit according to the embodiment.

[0015] Figure 3 It is a plan view showing the electronic unit according to the embodiment.

[0016] Figure 4 It is a side view showing the electronic unit according to the embodiment.

[0017] Figure 5 It is an exploded perspective view showing the electronic unit according to the embodiment.

[0018] Figure 6 It is along Figure 2 Cross-sectional view along line VI-VI.

[0019] Figure 7 yes Figure 6 Magnified view of area A in FIG.

[0020] Figure 8 It is along Figure 2 Cross-sectional view along line VIII-VIII in FIG.

[0021] Fig. 9 yes Figure 8 Magnified view of area B in FIG. DETAILED DESCRIPTION

[0022] [Description of Embodiments of the Present Disclosure]

[0023] First, embodiments of the present disclosure are listed for description.

[0024] The electronic unit of the present disclosure is as follows.

[0025] (1) An electronic unit comprises: a housing having an opening; a circuit board received in the housing through the opening; and a cover mounted on the opening, wherein a protrusion is provided on at least one side wall of the housing, the protrusion being configured to include a step that causes a portion of the side wall on the opening to protrude further outward than a portion on the inner side and extending along the periphery of the opening. The protrusion is formed on the side wall of the housing, so that water flowing along the side wall of the housing is intercepted by the protrusion and is not likely to reach a gap between the housing and the cover.

[0026] (2) A plurality of the protrusions may be provided on at least one side wall of the housing from the inner side portion toward the opening side portion. The plurality of protrusions are provided on the side wall of the housing, so that water flowing on the side wall of the housing is easily intercepted by the protrusions.

[0027] (3) The protrusions may be provided on three or more side walls of the housing. In this way, the protrusions can be located on the side wall that becomes the upper surface regardless of whether the housing is arranged vertically or horizontally.

[0028] (4) Alternatively, the housing may include a first side wall and a second side wall connected to each other, the second side wall may include a locking portion that is locked with the cover, the protrusion on the second side wall may include a first belt-shaped protrusion that is formed in a belt shape, and the first belt-shaped protrusion may be provided in a manner that extends along the circumferential direction of the opening at a position farther from the opening than the locking portion. Thus, water does not easily reach the locking portion. Water can be prevented from intruding into the gap in the locking portion.

[0029] (5) The first strip-shaped protrusion may be provided so as to protrude to the outside of the second side wall to a greater extent than the locking portion. This makes it difficult for water to reach the locking portion.

[0030] (6) The protrusion on the first side wall may include an opening-side protrusion, the opening-side protrusion being provided at a position closer to the opening than the first strip-shaped protrusion, and the protrusion on the second side wall may further include a second strip-shaped protrusion connecting the opening-side protrusion and the first strip-shaped protrusion. Thus, the protrusion of the first side wall can be located close to the opening.

[0031] (7) The first strip-shaped protrusion and the second strip-shaped protrusion may divide the second side wall into an opening side region and a back side region, and the surfaces of the first strip-shaped protrusion and the second strip-shaped protrusion facing the back side region may be inclined surfaces, and the inclined surfaces may be inclined from the base end connected to the second side wall toward the front end and away from the back side region. Thus, when the electronic unit is arranged so that the first side wall faces upward in the vertical direction, water can easily flow along the inclined surfaces.

[0032] [Details of the embodiments of the present disclosure]

[0033] Specific examples of the electronic unit of the present disclosure are described below with reference to the drawings. In addition, the present disclosure is not limited to these examples, but is indicated by the claims, and is intended to include all changes within the meaning and scope equivalent to the claims.

[0034] [Implementation Method]

[0035] Hereinafter, an electronic unit according to the embodiment will be described. Figure 1 It is a perspective view showing the electronic unit 10 according to the embodiment. Figure 2 It is a front view showing the electronic unit 10 according to the embodiment. Figure 3 It is a plan view showing the electronic unit 10 according to the embodiment. Figure 4 It is a side view showing the electronic unit 10 according to the embodiment. Figure 5 It is an exploded perspective view showing the electronic unit 10 according to the embodiment. Figure 6 It is along Figure 2Cross-sectional view along line VI-VI. Figure 7 yes Figure 6 Magnified view of area A in FIG. Figure 8 It is along Figure 2 Cross-sectional view along line VIII-VIII in FIG. Fig. 9 yes Figure 8 Magnified view of area B in FIG.

[0036] The electronic unit 10 includes a housing 20, a circuit board 30, and a cover 40. The electronic unit 10 is used as, for example, an electronic control unit. The electronic unit 10 is mounted on a vehicle or the like. It is assumed that the electronic unit 10 is disposed in a location in the vehicle such as a vehicle interior where there is a low possibility of wading.

[0037] The housing 20 has an opening 21. The housing 20 is formed into a rectangular box shape. The portion of the rectangular parallelepiped corresponding to one of the six faces is the opening 21. Four of the six faces of the rectangular parallelepiped surrounding the opening 21 are set as side walls 22, 23, 24, and 25. The side wall 22 is equivalent to the first side wall 22. The side walls 23 and 24 are equivalent to the second side walls 23 and 24. The face located on the opposite side of the opening 21 among the six faces of the rectangular parallelepiped is set as the bottom wall 26. Hereinafter, in this specification, the direction connecting the opening 21 and the bottom wall 26 is set as the X direction. The X direction is the insertion direction of the circuit substrate 30. Two directions orthogonal to the X direction are set as the Y direction and the Z direction. The Y direction is parallel to the side walls 22 and 25. The Z direction is parallel to the side walls 23 and 24.

[0038] The circuit substrate 30 is received in the housing 20 through the opening 21. Electronic components may be mounted on the circuit substrate 30. The circuit substrate may be one layer, two layers, or three layers or more. A connector C is provided on the circuit substrate 30. The entire circuit substrate 30 along the X direction is received in the housing 20.

[0039] The connector C includes a connector housing H and a terminal T. The connector housing H is placed on a circuit substrate 30. A portion of the connector housing H protrudes outwardly from the circuit substrate 30 along the X direction. A portion of the connector housing H protrudes outwardly from the housing 20 along the X direction. A counterpart connector is connected to the protruding portion. A recess is formed in the protruding portion. The counterpart connector is inserted into the recess. One end of the terminal T is connected to a circuit in the circuit substrate 30. The other end of the terminal T protrudes into the recess. When the counterpart connector is inserted into the recess, the other end of the terminal T is connected to a counterpart terminal provided on the counterpart connector.

[0040] A positioning portion for positioning the circuit board 30 may also be provided on the inner surface of the housing 20. Figure 5In the figure, a guide portion 27 is shown as the positioning portion. The guide portion 27 is formed on the inner surface of the side walls 23 and 24. The guide portion 27 is formed in a groove shape extending along the X direction. The circuit substrate 30 inserted from the opening 21 is guided by the guide portion 27 and accommodated in the housing 20. The guide portion 27 is formed to support the side edge of the circuit substrate 30 when the circuit substrate 30 is accommodated in the housing 20. In addition, as the positioning portion, for example, a convex portion may be provided on one of the inner surface of the housing 20 and the circuit substrate 30, and a concave portion for the convex portion to fit into may be provided on the other.

[0041] The outer surface of the housing 20 is provided with a locking portion 28 capable of locking the cover 40. Here, the locking portion 28 is provided on the outer surface of the side walls 23 and 24. The locking portion 28 is formed in a protrusion shape protruding from the outer surface of the side walls 23 and 24. The cover 40 is hooked and locked to the locking portion 28.

[0042] The cover 40 is mounted on the opening 21 . The cover 40 includes a frame 41 , an outward flange 42 , a cover body 43 , and an inward flange 44 . The cover 40 includes a rib 45 and a locking piece 46 .

[0043] The frame 41 is inserted into the housing 20 from the opening 21. The frame 41 is formed into a shape along the inner peripheral surface of the peripheral edge of the opening 21. The side walls 22, 23, 24, and 25 are provided as the peripheral edge of the opening 21, and therefore the frame 41 is formed into a rectangular parallelepiped cylindrical shape corresponding to the inner surface shape of the side walls 22, 23, 24, and 25. The outer surface of the frame 41 is provided in a manner facing the inner surface of the side walls 22, 23, 24, and 25 at a distance.

[0044] The outward flange 42 extends from the frame 41 toward the inner surface of the housing 20. The outward flange 42 is connected to one end of the frame 41 located on the inner side of the housing 20. The outward flange 42 blocks the gap between the frame 41 and the housing 20.

[0045] The cover 43 is formed to surround the periphery of the connector housing H. Here, three connectors C are provided. Three cover bodies 43 are provided in a manner to surround the periphery of the three connector housings H, respectively. Each cover body 43 is connected to the other end of the frame portion 41. Each cover body 43 protrudes further to the outside of the housing 20 than the frame portion 41 along the X direction. Each cover body 43 has an inner surface corresponding to the outer surface of the connector housing H. Here, the outer surface of each connector housing H is formed in a square shape, so each cover body 43 is formed in a rectangular parallelepiped cylindrical shape. One end of the cover body 43 protrudes further to the outside than the connector housing H along the X direction.

[0046] The inward flange 44 protrudes from the cover body 43 toward the outer surface of the connector housing H. The inward flange 44 is connected to the end of the cover body 43 located on the inner side of the housing 20. The portion where the frame 41 and the cover body 43 are connected is provided on the opposite side of the inward flange 44 relative to the cover body 43. The frame 41 is connected to the extended portion of the inward flange 44. A rib 45 is provided at the end of the inward flange 44. The inward flange 44 blocks the gap between the cover body 43 and the connector housing H.

[0047] The rib 45 protrudes from the front end of the inner flange 44 toward the inner side of the housing 20. The rib 45 surrounds the connector housing H. In addition, the rib 45 is arranged to face the frame 41. The rib 45 has a depth dimension that is the same as the depth dimension of the frame 41. On the side of the side wall 25, the end of the circuit substrate 30 on the opening 21 side is accommodated between the frame 41 and the rib 45. At this time, a clamping portion for clamping the end of the circuit substrate 30 may also be provided between the frame 41 and the rib 45. Thereby, the end of the circuit substrate 30 on the opening 21 side is supported.

[0048] The locking piece 46 is provided on the outer side of the frame 41. The locking piece 46 protrudes from the frame 41. The locking piece 46 includes a first piece and a second piece. The first piece protrudes from the frame 41 along the Y direction. The second piece protrudes from the front end of the first piece along the X direction. The second piece faces the side walls 23 and 24. A locking recess is formed in the second piece. By accommodating the locking portion 28 in the locking recess, the locking piece 46 is hooked and locked to the locking portion 28.

[0049] The locking recess is formed in the middle area between the first piece and the second piece. Thus, the two L-shaped pieces exist in parallel between the first piece and the middle area of ​​the second piece. Positioning recesses are formed around the opening 21 of the side walls 23 and 24 to position the two L-shaped pieces.

[0050] In the electronic unit of the present disclosure, water flowing along the outer surface of the housing 20 is prevented from intruding into the housing 20 by the protrusions 50 , 52 , 54 provided on the side walls 22 , 23 , 24 and the intervals set in the cover 40 .

[0051] <Protrusion>

[0052] First, the protrusions 50, 52, and 54 are described. The protrusions 50, 52, and 54 are provided to prevent water from reaching the gap between the cover 40 and the housing 20 and the gap between the cover 40 and the connector housing H. Here, a plurality of protrusions 50 and 52 are provided on the side wall 22. In addition, protrusions 54 are provided on the side walls 23 and 24, respectively. Each protrusion 50, 52, and 54 includes a step S that makes the opening 21 side portion of the side wall 22, 23, and 24 protrude further outward than the inner side portion. Each protrusion 50, 52, and 54 is provided to extend along the periphery of the opening 21.

[0053] In the side wall 22, a plurality of (two in this case) protrusions 50, 52 are provided from the back side portion toward the opening 21 side portion. The plurality of protrusions 50, 52 are provided at intervals in the X direction. Among the plurality of protrusions 50, 52, the protrusion located closest to the opening 21 is referred to as the opening side protrusion 50. In addition, among the plurality of protrusions 50, 52, the protrusion located farther from the opening 21 than the opening side protrusion 50 is referred to as the back side protrusion 52.

[0054] In the opening-side protrusion 50, the shape protruding outward from the opening 21 side further than the step S is continuous with the opening 21 side along the X direction. In addition, the inner surface of the portion of the side wall 22 where the opening-side protrusion 50 is formed is also stepped. Therefore, in the portion where the opening-side protrusion 50 is formed, the storage space in the housing 20 becomes larger. The cover 40 is stored in the enlarged storage space. Therefore, the opening-side protrusion 50 also has the function of enlarging the storage space in the housing 20 in order to store the cover 40.

[0055] Similarly, the inner protrusion 52 has a shape that protrudes outward from the opening 21 side more than the step S and is continuous with the opening 21 side along the X direction. In addition, the inner surface of the portion of the side wall 22 where the inner protrusion 52 is formed is also stepped. Therefore, the accommodation space in the housing 20 is enlarged in the portion where the inner protrusion 52 is formed. The connector housing H is accommodated in this enlarged accommodation space. Therefore, the inner protrusion 52 also has the function of enlarging the accommodation space in the housing 20 in order to accommodate the connector housing H.

[0056] The Y-direction middle portion of the surface facing the X-direction in the opening-side protrusion 50 protrudes most in the X-direction. Furthermore, the surface facing the X-direction in the opening-side protrusion 50 is inclined so as to gradually approach the opening 21 side as it approaches the Y-direction end from the Y-direction middle portion. Thus, water in contact with the surface facing the X-direction in the opening-side protrusion 50 is easily guided to the Y-direction end.

[0057] The surface of the opening-side protrusion 50 facing the X direction is orthogonal to the XY plane. On the other hand, the surface of the back-side protrusion 52 facing the X direction forms an angle of less than 90 degrees with respect to the XY plane. However, the surface of the opening-side protrusion 50 facing the X direction may also form an angle of less than 90 degrees with respect to the XY plane. In addition, the surface of the back-side protrusion 52 facing the X direction may also be orthogonal to the XY plane.

[0058] The protrusion 54 on the side walls 23 and 24 has a first belt-shaped protrusion 55 and a second belt-shaped protrusion 56. The first belt-shaped protrusion 55 and the second belt-shaped protrusion 56 are formed in a belt shape. The first belt-shaped protrusion 55 and the second belt-shaped protrusion 56 are formed to protrude outwards more than the portions located on both sides thereof.

[0059] The first strip-shaped protrusion 55 is provided so as to extend along the circumferential direction of the opening 21 at a position farther from the opening 21 than the locking portion 28. The first strip-shaped protrusion 55 is provided so as to protrude to the outside of the second side walls 23 and 24 more than the locking portion 28. The first strip-shaped protrusion 55 is provided so as to protrude more than the locking portion 28 in the Y direction. The first strip-shaped protrusion 55 is provided at a position farther from the opening 21 than the opening-side protrusion 50 in the X direction. That is, the opening-side protrusion 50 is provided at a position closer to the opening 21 than the first strip-shaped protrusion 55 in the X direction. The first strip-shaped protrusion 55 extends in the Z direction. One end of the first strip-shaped protrusion 55 reaches the side wall 25. The other end of the first strip-shaped protrusion 55 stops at the middle part of the side walls 22 and 23. The position of the other end of the first strip-shaped protrusion 55 relative to the side wall 25 along the Z direction is located at the same position as or farther away from the position of the part of the side wall 22 that is closer to the inner side than the inner side protrusion 52 relative to the side wall 25.

[0060] The second strip-shaped protrusion 56 connects the opening-side protrusion 50 and the first strip-shaped protrusion 55. The second strip-shaped protrusion 56 includes a first portion 57 and a second portion 58.

[0061] The first portion 57 is a portion extending in the Z direction. The first portion 57 is provided at a position away from the first belt-shaped protrusion 55 in the X direction. The first portion 57 is provided at a position closer to the opening 21 than the first belt-shaped protrusion 55 in the X direction. The first portion 57 extends in parallel with the first belt-shaped protrusion 55. One end of the first portion 57 is connected to the opening-side protrusion 50. The other end of the first portion 57 is located at the same position as the other end of the first belt-shaped protrusion 55 in the Z direction.

[0062] The second portion 58 connects the first belt-shaped protrusion 55 and the first portion 57. The second portion 58 extends along the X direction. One end of the second portion 58 is connected to the other end of the first belt-shaped protrusion 55. The other end of the second portion 58 reaches the opening 21. The other end of the first portion 57 is connected to the middle portion of the second portion 58.

[0063] The first strip-shaped protrusion 55 and the second strip-shaped protrusion 56 divide the second side walls 23 and 24 into an opening side area and a back side area. The opening side area is an area on the side where the locking portion 28 is located. The back side area is an area on the side connected to the bottom wall 26. The surfaces of the first strip-shaped protrusion 55 and the second strip-shaped protrusion 56 that face the back side area are inclined surfaces. The inclined surfaces are inclined in a manner that moves away from the back side area from the base end connected to the second side walls 23 and 24 toward the front end.

[0064] Specifically, the surface of the first strip-shaped protrusion 55 that faces the inner side (positive side in the X direction) is an inclined surface. In addition, the surface of the first portion 57 that faces the inner side (positive side in the X direction) is an inclined surface. The inclined surface of the first strip-shaped protrusion 55 and the inclined surface of the first portion 57 are inclined toward the negative side in the X direction as they protrude from the side walls 23 and 24 along the Y direction. The surface of the second portion 58 that faces the side wall 22 (positive side in the Z direction) is an inclined surface. The inclined surface of the second portion 58 is inclined toward the negative side in the Z direction as it protrudes from the side walls 23 and 24 along the Y direction.

[0065] <interval>

[0066] The gap is described below. By setting the gap in the cover 40 , even if water reaches the gap between the cover 40 and the housing 20 or the gap between the cover 40 and the connector C, the water is unlikely to enter the housing 20 .

[0067] Specifically, in Figure 7 and Fig. 9 In the figure, dimension C1 is the distance between the outer surface of the frame 41 and the inner surface of the housing 20. Dimension Z1 is the dimension of the portion where the outer surface of the frame 41 and the inner surface of the housing 20 face each other along the X direction (depth direction). Dimension C1 and dimension Z1 are determined by the following formula (1).

[0068] [Number 1]

[0069]

[0070] Here, formula (1) is a formula representing the liquid level when capillary action occurs in a circular tube. In formula (1), Z is the liquid level (m). In addition, T is the surface tension (N / m). In addition, θ is the contact angle (rad). In addition, ρ is the density of the liquid (kg / m 3 ). g is the acceleration due to gravity (m / s 2 ). r is the radius of the tube (m). In formula (1), the liquid level Z is inversely proportional to the radius r of the tube. T and ρ are inherent values ​​in the liquid. In addition, Θ is a value determined by the material and liquid that constitute the tube. Therefore, when the type of material and liquid that constitute the tube is determined, the variables are only Z and r.

[0071] The value of Z1 is set to a value that is the same as or larger than the value of Z obtained when half of the value of C1 is substituted into the value of r in formula (1). In addition, C1 and Z at this time can also be obtained through experiments. That is, the value of Z1 is set to a value that is the same as or larger than the value of Z obtained when an experiment is conducted using a circular tube and water having a radius of half the value of C1. At this time, the value of Z can also be obtained in two cases, namely, the case where the circular tube is made of the material constituting the cover 40 and the case where the circular tube is made of the material constituting the shell 20. In this case, the value of Z1 can be set to a value that is the same as or larger than the larger of the two values ​​of Z, or it can be set to a value that is the same as or larger than the smaller value, or it can be set to a value that is the same as or larger than the average of the two values ​​of Z.

[0072] By setting the values ​​of C1 and Z1 in this way, water that has penetrated between the outer surface of the frame 41 and the inner surface of the housing 20 is less likely to penetrate into the housing 20 even if the capillary phenomenon occurs.

[0073] In addition, when the gap between the outer surface of the frame 41 and the inner surface of the housing 20 is large, dust, garbage, etc. may enter the housing 20 through the gap. However, the outward flange 42 is provided, so that the dust, garbage, etc. that pass through the gap between the outer surface of the frame 41 and the inner surface of the housing 20 are suppressed from entering the housing 20. Here, even if the water that enters between the outer surface of the frame 41 and the inner surface of the housing 20 produces a capillary phenomenon, it is not easy to reach the outward flange 42. Therefore, when the outward flange 42 is provided as in this example, even if there is a small gap between the outer surface of the outward flange 42 and the inner surface of the housing 20, water is not easy to reach the gap, so water is not easy to enter the housing 20 through the gap.

[0074] Similarly, in Figure 7 and Fig. 9 , dimension C2 is the distance between the inner surface of the cover body 43 and the outer surface of the connector housing H. Dimension Z2 is the dimension along the X direction (depth direction) of the portion where the inner surface of the cover body 43 faces the outer surface of the connector housing H. Dimension C2 and dimension Z2 are also determined according to the above-mentioned formula (1).

[0075] The value of Z2 is set to a value that is the same as or larger than the value of Z obtained when the value of r is substituted into the value of half of the above-mentioned C2 in formula (1). In addition, C2 and Z at this time can also be obtained through experiments. That is to say, the value of Z2 is set to a value that is the same as or larger than the value of Z obtained when an experiment is performed using a circular tube with a radius of half the value of C2. At this time, the value of Z can also be obtained in two cases, the case where the circular tube is made of the material constituting the cover 40 and the case where the material constituting the connector housing H is made of two materials. In this case, the value of Z2 can be set to a value that is the same as or larger than the value of the larger of the two Z values, or it can be set to a value that is the same as or larger than the value of the smaller one, or it can be set to a value that is the same as or larger than the average value of the two Z values.

[0076] By setting the values ​​of C2 and Z2 in this way, water that has penetrated between the inner surface of the cover 43 and the outer surface of the connector housing H is less likely to penetrate into the housing 20 even if the capillary phenomenon occurs.

[0077] In addition, when the gap between the inner surface of the cover body 43 and the outer surface of the connector housing H is large, dust, dirt, etc. may enter the housing 20 through the gap. However, the inward flange 44 is provided, so that dust, dirt, etc. that pass through the gap between the inner surface of the cover body 43 and the outer surface of the connector housing H are suppressed from entering the housing 20. Here, even if the water that enters between the inner surface of the cover body 43 and the outer surface of the connector housing H produces a capillary phenomenon, it is not easy to reach the inward flange 44. Therefore, when the inward flange 44 is provided as in this example, even if there is a small gap between the outer surface of the inward flange 44 and the outer surface of the connector housing H, water is not easy to reach the gap, so water is not easy to enter the housing 20 through the gap.

[0078] <Action>

[0079] When the housing 20 is arranged in a state where the side wall 22 faces vertically upward, the behavior of water when water hangs on the side wall 22 will be considered.

[0080] Water flowing along the outer surface of the side wall 22 sometimes moves from the inner side toward the opening 21 side. For example, the housing 20 is sometimes installed in a manner that the opening 21 is slightly downward. In this case, water flowing along the outer surface of the side wall 22 moves from the inner side toward the opening 21 side. When water flowing along the outer surface of the side wall 22 moves from the inner side toward the opening 21 side, it first reaches the inner protrusion 52. At this time, a step S is provided at the inner protrusion 52, so the water is intercepted by the step S. In addition, water that has passed the step S at the inner protrusion 52 reaches the opening-side protrusion 50. At this time, a step S is provided at the opening-side protrusion 50, so the water is intercepted by the step S.

[0081] The steps S at the opening-side protrusion 50 and the back-side protrusion 52 are formed to extend around the opening 21. Therefore, the water intercepted by the steps S advances toward the adjacent side walls 23 and 24 along the steps S. Then, the water flows downward along the adjacent side walls 23 and 24.

[0082] In addition, the side walls 23 and 24 are provided with protrusions 54, so that water reaching the side walls 23 and 24 is intercepted by the step S at the protrusions 54 and guided downward. At this time, there is a locking portion 28 near the protrusions 54, but the protrusions 54 protrude more than the locking portion 28, so it is not easy for water to reach the locking portion 28.

[0083] This makes it difficult for water to reach the gap between the cover 40 and the housing 20 and the gap between the cover 40 and the connector C.

[0084] Next, consider a case where some water reaches the gap between the cover 40 and the housing 20 and the gap between the cover 40 and the connector C. As described above, the protrusions 50, 52, and 54 prevent water from reaching the gap between the cover 40 and the housing 20 and the gap between the cover 40 and the connector C. However, there is a possibility that some water directly reaches the gap between the cover 40 and the housing 20 and the gap between the cover 40 and the connector C.

[0085] In this case, the dimensions C1 and Z1 are set to dimensions corresponding to the above formula (1), so that water is not easy to penetrate from the gap between the cover 40 and the housing 20 to the inner side of the cover 40 in the housing 20. Similarly, the dimensions C2 and Z2 are also set to dimensions corresponding to the above formula (1), so that water is not easy to penetrate from the gap between the cover 40 and the connector housing H to the inner side of the cover 40 in the housing 20.

[0086] As described above, water flowing along the outer surface of the housing 20 is less likely to enter the housing 20 .

[0087] <Effects of Implementation Methods, etc.>

[0088] According to the electronic unit 10 constructed as described above, the protrusions 50 , 52 , 54 are formed on the side walls 22 , 23 , 24 of the housing 20 , so that water flowing along the side walls 22 , 23 , 24 of the housing 20 is intercepted by the protrusions 50 , 52 , 54 and is unlikely to reach the gap between the housing 20 and the cover 40 .

[0089] Here, in order to make the electronic unit 10 waterproof, it is conceivable to attach a gasket or use a waterproof connector. However, these structures are expensive or complicated to manufacture. In addition, the parts with low possibility of wading may become oversized. In contrast, in the above-mentioned electronic unit 10, it is possible to easily have waterproofness, so the configuration of the parts with low possibility of wading is effective.

[0090] Furthermore, since the protrusions 50, 52, 54 are provided on three or more side walls 22, 23, 24 of the housing 20, any one of the protrusions 50, 52, 54 can be located on the side wall 22, 23, 24 that faces upward in the vertical direction, regardless of whether the housing 20 is disposed vertically or horizontally. In other words, any one of the protrusions 50, 52, 54 can be located regardless of which side wall 22, 23, 24 faces upward in the vertical direction.

[0091] In addition, since the plurality of protrusions 50 , 52 are provided on the side wall 22 of the housing 20 , water flowing along the side wall 22 of the housing 20 is easily intercepted by the protrusions 50 , 52 .

[0092] In addition, since the first strip-shaped protrusion 55 is provided at a position farther from the opening 21 than the locking portion 28, water is unlikely to reach the locking portion 28. The intrusion of water from the gap in the locking portion 28 can be suppressed.

[0093] Furthermore, since the first strip-shaped protrusion 55 is provided to protrude to the outside of the second side walls 23 , 24 to a greater extent than the locking portion 28 , water is unlikely to reach the locking portion 28 .

[0094] Furthermore, since the opening-side protrusion 50 and the second strip-shaped protrusion 56 are provided, the step S at the opening-side protrusion 50 can be located close to the opening 21 . Thus, even if water reaches the vicinity of the opening 21 in the side wall 22 , the water can be intercepted by the opening-side protrusion 50 .

[0095] Furthermore, when the electronic unit 10 is disposed in a vehicle or the like with the side wall 22 facing upward in the vertical direction, water easily flows along the inclined surfaces of the first strip-shaped protruding portion 55 and the second strip-shaped protruding portion 56. Thus, water easily flows downward.

[0096] [Modifications]

[0097] In the embodiment, the structure in which the protrusions 50, 52, 54 are formed on a plurality of side walls 22, 23, 24 is described, but this is not a necessary structure. The protrusion may be formed on only one side wall. The protrusion only needs to be provided on at least one side wall of the housing. In addition, the protrusion may be provided on three or more side walls of the housing. The protrusion may also be provided on three or more side walls of four consecutive side walls in the cuboid.

[0098] In the embodiment, the structure in which the side wall 22 is provided with a plurality of protrusions 50, 52 is described, but this is not a necessary structure. The housing may not have a side wall provided with a plurality of protrusions. In other words, the number of protrusions in all the side walls of the housing may be one or less.

[0099] In the embodiment, the protrusion 54 on the second side walls 23 and 24 has the first strip-shaped protrusion 55 and the second strip-shaped protrusion 56, but this is not a necessary structure. The protrusion 54 on the second side walls 23 and 24 can also be formed in the same shape as the opening-side protrusion 50 on the first side wall 22.

[0100] In addition, the protrusion 54 on the second side walls 23 and 24 may have only the first strip-shaped protrusion 55. In this case, the step S at the opening-side protrusion 50 and the step S at the first strip-shaped protrusion 55 may be located at the same position in the X direction. In addition, the second strip-shaped protrusion 56 may not have the first portion 57 and the second portion 58. For example, the second strip-shaped protrusion extends on the side walls 23 and 24 in a manner that directly connects the opening-side protrusion 50 and the first strip-shaped protrusion 55.

[0101] In addition, the structure in which the protrusion dimension of the first strip-shaped protrusion 55 is larger than the locking portion 28 is described, but this is not necessarily a structure. The protrusion dimension of the first strip-shaped protrusion 55 may be the same as or smaller than the protrusion dimension of the locking portion 28.

[0102] In addition, although the structure in which the inclined surface is formed in the first belt-shaped protrusion 55 and the second belt-shaped protrusion 56 is described, this is not an essential structure. The inclined surface may not be formed in one or both of the first belt-shaped protrusion 55 and the second belt-shaped protrusion 56.

[0103] In addition, the structure in which the distance between the cover 40 and the housing 20 and the distance between the cover 40 and the connector housing H are set according to the formula (1) is described, but this is not a necessary structure. The distance between the cover 40 and the housing 20 and the distance between the cover 40 and the connector housing H may be set regardless of the formula (1).

[0104] In addition, the respective configurations described in the above-mentioned embodiment and the respective modifications can be appropriately combined as long as they do not contradict each other.

[0105] Description of Reference Numerals

[0106] 10 Electronic unit

[0107] 20 Shell

[0108] 21 Opening

[0109] 22 side wall (first side wall)

[0110] 23 side wall (second side wall)

[0111] 24 side wall (second side wall)

[0112] 25 Sidewall

[0113] 26 bottom wall

[0114] 27 Guidance

[0115] 28. Carding Department

[0116] 30 Circuit board

[0117] 40 Cover

[0118] 41 Frame

[0119] 42 Outward facing flange

[0120] 43. Cover

[0121] 44 Inward flange

[0122] 45 Ribs

[0123] 46 card plate

[0124] 50 Protrusion (opening side protrusion)

[0125] 52 protrusion (inner protrusion)

[0126] 54 Protrusion

[0127] 55 First ribbon-like protrusion

[0128] 56 Second ribbon-like protrusion

[0129] 57 Part 1

[0130] 58 Part 2

[0131] C Connector

[0132] H Connector Housing

[0133] T Terminal

[0134] S steps.

Claims

1. An electronic unit comprising: a housing having an opening; a circuit substrate received in the housing through the opening; and a cover mounted on the opening, At least one side wall of the housing is provided with a protrusion, The protrusion is provided to include a step that causes a portion of the side wall on the side of the opening to protrude further outward than a portion on the inner side and to extend along the periphery of the opening. The housing has a first side wall and a second side wall connected to each other. The second side wall is provided with a locking portion for locking with the cover. The first side wall protrudes outward from the outer surface of the cover, The protrusion includes a protrusion formed on the first side wall, The protrusion formed on the first side wall includes an inner protrusion and an opening side protrusion that are spaced apart from the inner side portion of the first side wall toward the opening side portion, and the steps at the inner protrusion and the opening side protrusion are respectively formed in a manner extending around the opening to intercept water flowing from the inner side to the opening side along the outer surface of the first side wall.

2. The electronic unit according to claim 1, wherein: The protrusions are provided on three or more side walls of the housing.

3. The electronic unit according to claim 1 or 2, wherein: The protrusion on the second side wall has a first strip-shaped protrusion formed in a strip shape, The first belt-shaped protrusion is provided at a position farther from the opening than the locking portion so as to extend along the circumferential direction of the opening.

4. The electronic unit according to claim 3, wherein: The first strip-shaped protrusion is provided to protrude toward the outside of the second side wall to a greater extent than the locking portion.

5. The electronic unit according to claim 3, wherein: The opening-side protrusion on the first side wall is arranged at a position closer to the opening than the first strip-shaped protrusion. The protrusion on the second side wall further includes a second belt-shaped protrusion connecting the opening-side protrusion and the first belt-shaped protrusion.

6. The electronic unit according to claim 4, wherein: The opening-side protrusion on the first side wall is arranged at a position closer to the opening than the first strip-shaped protrusion. The protrusion on the second side wall further includes a second belt-shaped protrusion connecting the opening-side protrusion and the first belt-shaped protrusion.

7. The electronic unit according to claim 5, wherein: The first strip-shaped protrusion and the second strip-shaped protrusion divide the second side wall into an opening side area and a back side area. The surfaces of the first belt-shaped protrusion and the second belt-shaped protrusion facing the back area are inclined surfaces. The inclined surface is inclined from a base end connected to the second side wall toward a front end so as to be away from the back side area.

8. The electronic unit according to claim 6, wherein: The first strip-shaped protrusion and the second strip-shaped protrusion divide the second side wall into an opening side area and a back side area. The surfaces of the first belt-shaped protrusion and the second belt-shaped protrusion facing the back area are inclined surfaces. The inclined surface is inclined from a base end connected to the second side wall toward a front end so as to be away from the back side area.

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