Water immersion suppression structure

Abstract

To suppress immersion of water.SOLUTION: A water immersion suppression structure includes: a case 2 having a peripheral wall part 22; and a cover 3 that seals an open of the peripheral wall part 22 from a direction of a shaft line X along an open direction of the peripheral wall part 22. The cover 3 comprises an outer wall part 32 inserted into the peripheral wall part 22 from the direction of the shaft line X. In a view of a radial direction of the shaft line X, there is the minimum region where a gap of the peripheral wall part 22 and the outer wall part 32 become the minimum in an overlapping region where the peripheral wall part 22 and the outer wall part 32 are overlapped. On the one side and the other side of the minimum region in the shaft line X direction, an expansion region that the gap between the peripheral wall part 22 and the outer wall part 32 is larger than the minimum region is provided respectively.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a water ingress prevention structure. [Background technology]

[0002] Patent Document 1 discloses a structure for preventing water from entering a switch device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-194902 A Summary of the Invention [Problem to be solved by the invention]

[0004] The main body case of the switch device in Patent Document 1 is formed by inserting a cylindrical wall portion of the cover into a peripheral wall portion of the case. In the main body case, there is a small gap between the peripheral wall portion of the case and the cylindrical wall portion of the cover. Therefore, moisture adhering to the outer periphery of the main body case may be drawn into the gap by capillary action and may penetrate into the inside of the main body case.

[0005] A protrusion for supporting the printed circuit board is provided at the tip of the cylindrical wall on the cover side. A plurality of protrusions are provided at intervals in the circumferential direction. Each of the protrusions is provided at an interval between itself and the inner periphery of the peripheral wall on the case side. In Patent Document 1, the gap between the protrusion and the peripheral wall portion on the case side is made wider than the gap between the peripheral wall portion on the case side and the cylindrical wall portion on the cover side, so that even if moisture seeps into the gap due to capillary action and reaches the inside of the main case, it is less likely to reach the printed circuit board.

[0006] However, it is preferable to prevent moisture from entering the inside. In addition to such requirements, another objective of the present invention is to achieve actions and effects derived from the configurations disclosed in the "Form for implementing the invention" described below, which actions and effects cannot be obtained with conventional technologies. [Means for solving the problem]

[0007] The present invention relates to A first housing having a wall portion along an axial direction; a second housing that is assembled to the first housing from the axial direction and has an insertion wall that is inserted into the wall portion from the axial direction, When viewed from the radial direction of the axis, in the overlapping region where the wall portion and the insertion wall overlap, there is a minimum region where the gap between the wall portion and the insertion wall is smallest, and on at least one side of the minimum region in the axial direction, there is an expanded region where the gap between the wall portion and the insertion wall is wider than the minimum region, and the one side viewed from the minimum region is configured to be connected to the inside of the first housing, thereby forming a water-proof structure. Effect of the Invention

[0008] According to the present invention, it is possible to suppress the intrusion of moisture into the interior. [Brief description of the drawings]

[0009] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. 2 is a perspective view showing a cross section of the switch device. [Figure 9]FIG. 2 is a perspective view showing a cross section of the switch device. [Figure 10] FIG. 4 is a cross-sectional view of a portion of the water ingress prevention structure. [Figure 11] FIG. 4 is a cross-sectional view of a portion of the water ingress prevention structure. [Figure 12] 10A and 10B are diagrams illustrating the function of the water ingress prevention structure. [Figure 13] 11A to 11C are diagrams illustrating the process of creating a cover. [Figure 14] 13A and 13B are diagrams illustrating a water ingress prevention structure according to a modified example. [Figure 15] 13A and 13B are diagrams illustrating a water ingress prevention structure according to a modified example. [Figure 16] 13A and 13B are diagrams illustrating a water ingress prevention structure according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described taking as an example a switch device 1 used to specify a driving mode of a vehicle. Fig. 1 is an exploded perspective view of the switch device 1. Fig. 2 is a perspective view of the switch device 1. Figs. 3 and 4 are cross-sectional views of the switch device 1. Fig. 3 is a schematic cross-sectional view of a switch 5A portion of the switch device 1 taken along plane A in Fig. 2. Fig. 4 is a schematic cross-sectional view of the switch 5A taken along line AA in Fig. 3. In the following description, for convenience of explanation, the positional relationship of each component will be described based on the vertical direction in Fig. 3. For example, when "upper side" is described, it means the upper side in the vertical direction in Fig. 3. Therefore, depending on the usage state of the switch device 1, even if "a component located on the upper side" is described, it may be located diagonally above or below. Furthermore, in each of the drawings used in the following description, for the convenience of explaining the invention, the gap between the peripheral wall portion 22 and the outer wall portion 32 and the like are exaggerated and shown diagrammatically.

[0011] As shown in FIGS. 1 and 2, the switch device 1 includes a total of four switches 5 (5A to 5D). An operated portion 51 of each switch 5 (5A to 5D) is exposed at the top of the case 2. A different function is assigned to each of the switches 5 (5A to 5D). As an example, if the switch device 1 is a switch device used to specify the driving mode of a vehicle, functions such as parking (P), reverse driving (R), neutral (N), and forward driving (D) are assigned to each of the switches 5A to 5D. In the switch device 1, when any one of the switches 5A to 5D is pressed, the function assigned to the pressed switch 5 is designated, and the designation of the function that had been designated up to that point is terminated.

[0012] As shown in FIG. 3, the switch 5A has an operated portion 51 that is operated by a user, and a movable body 6 that is displaced in conjunction with the operation of the operated portion 51. As shown in FIG. 4, the switch 5A further includes a magnet M attached to the movable body 6, and a magnetic sensor 7 (Hall IC: detection element) that detects a change in the magnetic force of the magnet M due to the displacement of the movable body 6.

[0013] As shown in FIG. 3, the printed circuit board 40 is supported by a cover 3 that closes the lower opening of the case 2. The main body case 4 of the switch device 1 is formed by assembling the case 2 and the cover 3 in the direction of the axis X along the operation direction of the switch 5A (operated portion 51).

[0014] The case 2 has a peripheral wall portion 22 that covers the entire outer periphery of the cover 3, and an upper wall portion 23 that extends from an upper portion of the peripheral wall portion 22. The upper wall portion 23 is inclined in a direction that narrows its outer diameter as it moves upward from the peripheral wall portion 22. A through hole 20 and a cylindrical wall portion 21 that surrounds the through hole 20 are provided in the upper portion of the upper wall portion 23. 1, the number of cylindrical wall portions 21 provided is the same as the number of switches 5 (5A to 5D). Each of the cylindrical wall portions 21 supports an operated portion 51 of each switch 5 (5A to 5D).

[0015] The configuration of the switch 5A will be described as a representative of the switches 5 (5A to 5D). 3, operated portion 51 of switch 5A has pressed portion 510, peripheral wall portion 511, and connecting portion 512. Peripheral wall portion 511 is a cylindrical portion surrounding the entire outer periphery of pressed portion 510. Connecting portion 512 extends inside peripheral wall portion 511 in the same direction as peripheral wall portion 511. A tip side of connecting portion 512 is inserted inside cylindrical wall portion 21 on the case 2 side.

[0016] In the case 2, the peripheral wall portion 511 of the operated portion 51 is fitted onto the outside of the cylindrical wall portion 21. Furthermore, in the case 2, the cylindrical wall portion 61 of the movable body 6 penetrates the inside of the cylindrical wall portion 21 in the direction of the axis X. Here, the axis X is a straight line perpendicular to the upper surface 40a of the printed circuit board 40 and is a straight line along the displacement direction of the movable body 6.

[0017] The movable body 6 is supported by the cylindrical wall portion 21 on the case 2 side so as to be movable in the direction of the axis X. In the movable body 6, the connecting portion 512 of the operated portion 51 is inserted inside the cylindrical wall portion 61. A protrusion 615 protruding from the inner circumference of the cylindrical wall portion 61 is engaged with an engagement hole 512a on the tip side of the connecting portion 512. In this embodiment, the protrusion 615 on the movable body 6 side is engaged with the engagement hole 512a, thereby connecting the operated portion 51 and the movable body 6. This allows the movable body 6 to be displaced in the direction of the axis X in conjunction with the pressing operation of the operated portion 51.

[0018] The cylindrical wall portion 61 of the movable body 6 is provided with contact portions 62, 62 at a lower portion on the opposite side to the operated portion 51 in the direction of the axis X. The contact portions 62, 62 bulge outward from the outer periphery of the cylindrical wall portion 61 in directions away from each other. The contact portions 62, 62 are placed on the placement portion 82 of the cover member 8.

[0019] FIG. 5 is a schematic diagram showing the cover member 8 as viewed from the case 2 side. For ease of explanation, Fig. 5 shows a simplified illustration without illustrating fine irregularities on the surface of the cover member 8. Furthermore, in Fig. 5, in order to explain the correspondence between the portions (placing portion 82, accommodating portion 83) protruding from the base portion 81 and the switches 5A to 5D, the corresponding portions (placing portion 82, accommodating portion 83) for each of the switches 5A to 5D are shown surrounded by dashed lines.

[0020] 3 and 4, the cover member 8 has a base portion 81, a mounting portion 82, and a storage portion 83. The cover member 8 is an integrated part made of a flexible elastic material such as rubber. It is formed to a size capable of covering the entire upper surface 40a of the printed circuit board 40. The base 81 is a portion that is placed on the printed circuit board 40 (see FIG. 3). The placement portion 82 is a portion that supports the movable body 6 so that the movable body 6 can be displaced in the direction of the axis X (the up-down direction in the figure) (see FIG. 3). The accommodation portion 83 is a portion that accommodates the magnetic sensor 7 and the support body 75 (see FIG. 4). 5, in the cover member 8, a pair of mounting portions 82, 82 and one storage portion 83 are assigned to one switch. In the figure, the mounting portions 82, 82 and the storage portion 83 in the area surrounded by a dashed line and labeled with the reference symbol 5A are the portions for the switch 5A. In the figure, the mounting portions 82, 82 and the storage portion 83 in the area surrounded by a dashed line and labeled with the reference symbol 5B are the portions for the switch 5B.

[0021] As shown in FIG. 3, when the operated portion 51 is pressed and an operating force toward the printed circuit board 40 is input to the movable body 6, the mounting portion 82 of the cover member 8 is pushed by the movable body 6 and displaced in a direction approaching the printed circuit board 40 while deforming the support wall portion 822. The placement portion 82 is displaced downward toward the printed circuit board 40 until the stopper portion 823 comes into contact with the printed circuit board 40 . When the operating force acting on the movable body 6 is released, the mounting portion 82 is displaced in a direction away from the printed circuit board 40 by the restoring force of the support wall portion 822 . The support wall portion 822 applies a biasing force to the movable body 6 in a direction that returns the movable body 6 placed on the placement portion 82 to its initial position before displacement.

[0022] In this embodiment, the movable body 6, which displaces in the direction of the axis X in response to the operation of the operated part 51, is placed on the mounting parts 82, 92, so that the user can feel the operation sensation (reaction force) when pressing the operated part 51. The entire upper surface 40a of the printed circuit board 40 is covered with a cover member 8. The peripheral portion of the cover member 8 is provided with a side wall portion 84 that surrounds the entire periphery. 3, the side wall portion 84 passes along the side of the printed circuit board 40 and extends downward toward the bottom wall portion 31 of the cover 3. A lower end 84a of the side wall portion 84 is inserted between the outer wall portion 32 and the inner wall portion 33 on the cover 3 side (see FIG. 8).

[0023] Fig. 6 is a plan view of the cover 3 as viewed from the case 2 side. Fig. 7 is a diagram showing a cross section of the cover 3 cut along line AA in Fig. 5, together with the case 2, the cover 3, and a cover member 8. Fig. 8 is a perspective view showing a cross section of the cover 3 cut along line BB in Fig. 5. Fig. 9 is a perspective view showing a cross section of the cover 3 cut along line CC in Fig. 5. Figures 10 and 11 are cross-sectional views of a portion of the water-ingress prevention structure 10. Figure 10 corresponds to an enlarged cross-section of region B in Figure 8, along with Case 2. Figure 11 corresponds to an enlarged cross-section of region A in Figure 9, along with Case 2. Figure 12 is a diagram explaining the function of the water-ingress prevention structure 10. Figure 12 corresponds to an enlarged cross-section of region A in Figure 11. In FIG. 6, the area of ​​the slits 35 is shown with cross-hatching to make the area of ​​the slits 35 easier to understand.

[0024] As shown in FIG. 3, the cover 3 has a bottom wall portion 31, an outer wall portion 32, and an inner wall portion 33. As shown in Fig. 6, the bottom wall portion 31 has a substantially rectangular shape in a plan view. The outer wall portion 32 has a cylindrical shape surrounding the outer peripheral edge of the bottom wall portion 31 all around. The outer wall portion 32 is provided in a direction substantially perpendicular to the upper surface 31a (see Fig. 3) of the bottom wall portion 31. The outer wall portion 32 is formed at substantially the same height all around in the circumferential direction. The outer wall portion 32 is an insertion wall that is inserted into the peripheral wall portion 22 when the lower opening of the case 2 (peripheral wall portion 22) is sealed with the cover 3.

[0025] The inner wall portion 33 is provided along the inner periphery of the outer wall portion 32. The inner wall portion 33 is provided with a gap between it and the outer wall portion 32. As shown in Fig. 6, the inner wall portion 33 also has a cylindrical shape in a plan view. The inner wall portion 33 is provided in a direction substantially perpendicular to the upper surface 31a of the bottom wall portion 31. The height h33 of the inner wall portion 33 is lower than the height h32 of the outer wall portion 32. The inner wall portion 33 is formed at substantially the same height over the entire circumference in the circumferential direction (see Fig. 3).

[0026] 6, in the cover 3, a groove 34 is formed between the outer wall portion 32 and the inner wall portion 33 in a plan view. The groove 34 has first groove portions 341, 341 along the long side of the bottom wall portion 31 and second groove portions 342, 342 along the short side of the bottom wall portion 31. The second groove portions 342, 342 connect the longitudinal ends of the first groove portions 341, 341 to each other. In the cover 3, the groove 34 is provided along the entire inner circumference of the outer wall portion 32 of the bottom wall portion 31.

[0027] In the first groove portions 341, 341, slits 35, 35 are provided at one end and the other end in the longitudinal direction (left-right direction in the drawings). Furthermore, in the first groove portions 341, 341, a slit 35 is also provided in the center in the longitudinal direction (left-right direction in the drawings). The slit 35 is formed by cutting out a region exposed between the outer wall portion 32 and the inner wall portion 33 in the bottom wall portion 31. The inside of the groove 34 and the outside of the cover 3 are in communication via the slit 35 (see FIGS. 3, 7, and 8).

[0028] A support base 36 for a printed circuit board 40 is provided on the inside of the inner wall portion 33. The support base 36 protrudes in the same direction as the outer wall portion 32. A plurality of support bases 36 are provided on the bottom wall portion 31. 3, a printed circuit board 40 is placed on the upper end of the support stand 36. A cover member 8 made of an elastic material is placed on the printed circuit board 40.

[0029] As shown in FIG. 4, the magnetic sensors 7 (7A, 7B, 7C) and the support 75 are accommodated in an accommodating portion 83 of a cover member 8 that covers the upper surface of the printed circuit board 40. A side wall 84 is provided around the entire periphery of the cover member 8. As shown in Fig. 3, the side wall 84 passes along the side of the printed circuit board 40 and extends downward toward the bottom wall 31 of the cover 3. As shown in Fig. 11, a lower end 84a of the side wall 84 is located lower on the bottom wall 31 side than a tip 33a of the inner wall 33 on the cover 3 side. The lower end 84a of the side wall 84 is inserted into a groove 34 between the inner wall 33 and the outer wall 32.

[0030] In this embodiment, the upper surface 40a of the printed circuit board 40 is covered with the cover member 8 together with the mounted components. Therefore, when moisture W penetrates into the inside of the main body case 4 from the switch 5 side, the penetrated moisture W is prevented from directly touching the printed circuit board 40. Furthermore, the penetrated moisture W moves on the surface of the cover member 8, runs along the side wall portion 84 on the periphery of the cover member 8, and flows into the groove 34 between the outer wall portion 32 and the inner wall portion 33. Then, the moisture W that has flowed into the groove 34 passes through the slit 35 that opens into the groove 34 and is discharged to the outside of the main body case 4 (see FIG. 10).

[0031] The cover 3 is attached to the case 2 with screws (not shown) in a state in which the outer wall portion 32 is fitted inside the peripheral wall portion 22 on the case 2 side. In this state, there is a very small gap between the peripheral wall portion 22 on the case 2 side and the outer wall portion 32 on the cover 3 side to enable the outer wall portion 32 to be inserted into the peripheral wall portion 22. In this embodiment, there is a possibility that moisture W may enter the gap between the peripheral wall portion 22 and the outer wall portion 32 due to capillary action.

[0032] Therefore, in this embodiment, a structure for preventing the infiltration of moisture W (water infiltration prevention structure 10) is provided in an area (overlapping area) where the peripheral wall 22 and the outer wall 32 overlap. Here, the overlapping area means an area where the peripheral wall 22 on the case 2 side overlaps with the outer wall 32 and bottom wall 31 on the cover 3 side when the main body case 4 is viewed from the radial direction of the axis X (see Figs. 10 and 11).

[0033] Specifically, as shown in FIG. 11, the outer periphery of the outer wall portion 32 is provided with a first inclined surface 321 in which the outer diameter r321 of the outer wall portion 32 becomes smaller toward the tip end 32a, and a second inclined surface 322 in which the outer diameter r322 becomes smaller toward the base end 32b. An intersection P32 between the first inclined surface 321 and the second inclined surface 322 is a minimum area where the gap between the outer wall portion 32 and the peripheral wall portion 22 on the case 2 side is minimum. Between the peripheral wall portion 22 and the outer wall portion 32, when viewed from the minimum area, there are provided enlarged areas on one side (the tip end 32a side) and the other side (the base end 32b) in the direction of the axis X, where the gap between the peripheral wall portion 22 and the outer wall portion 32 is wider than the minimum area. In the enlarged region on the tip 32a side, the gap between the peripheral wall portion 22 and the outer wall portion 32 becomes wider from the intersection point P32 toward the tip 32a. In the enlarged region on the base end 32b side, the gap between the peripheral wall portion 22 and the outer wall portion 32 becomes wider from the intersection point P32 toward the base end 32b.

[0034] Here, the absorption of moisture W by capillary action becomes less likely as the gap between the peripheral wall portion 22 and the outer wall portion 32 becomes larger. However, as the gap between the peripheral wall portion 22 and the outer wall portion 32 becomes larger, dust and the like become more likely to enter the inside of the main body case 4 through the gap.

[0035] In this embodiment, the inclination angle θb between the peripheral wall portion 22 and the second inclined surface 322 is set so that the gap between the peripheral wall portion 22 and the outer wall portion 32 becomes wider from the intersection point P32 toward the base end 32b. Therefore, in the portion of the second inclined surface 322, the gap between the peripheral wall portion 22 and the outer wall portion 32 becomes wider as it moves away from the minimum area. This widens the gap on the base end 32b side of the outer wall portion 32, which is the inlet for moisture W, thereby reducing the possibility of moisture W intrusion. Furthermore, by narrowing the gap between the peripheral wall portion 22 and the outer wall portion 32 toward the inside of the main body case 4 (the tip 32a side of the outer wall portion 32), if dust or the like intrudes from the base end 32b side, the intruded dust or the like is less likely to reach the intersection point P32, which is the minimum area.

[0036] Furthermore, the inclination angle θa between the peripheral wall portion 22 and the first inclined surface 321 is set so that the gap between the peripheral wall portion 22 and the outer wall portion 32 becomes wider from the intersection point P32, which is the minimum area, toward the tip 32a of the outer wall portion 32. Therefore, in the portion of the first inclined surface 321, the gap between the peripheral wall portion 22 and the outer wall portion 32 becomes wider as it moves away from the minimum region toward the tip 32a. The suction force due to the capillary phenomenon becomes weaker in the gap that becomes wider as it moves forward. The intersection point P32, which is the minimum region, is provided along the outer periphery of the outer wall portion 32 over the entire circumferential direction.

[0037] Therefore, as shown in FIG. 12, moisture W that penetrates into the gap between the peripheral wall portion 22 and the outer wall portion 32 from the second inclined surface 322 side and reaches the intersection point P32, which is the smallest area, spreads out beyond the intersection point P32, making it difficult for moisture W to penetrate into the gap between the first inclined surface 321 and the peripheral wall portion 22. As shown in Figure 2, it is easier for moisture W to move in a circumferential direction along the imaginary line Im than it is for moisture W to move beyond the imaginary line Im indicating the position of the smallest area in the figure and penetrate into the first inclined surface 321 side (the inside of the main body case 4). Therefore, the moisture W that reaches the intersection P32 moves in the circumferential direction rather than crossing the imaginary line Im and penetrating into the first inclined surface 321 side (the inside of the main body case 4). This makes it difficult for the moisture W to penetrate into the inside of the main body case 4 through the gap between the first inclined surface 321 and the peripheral wall portion 22. In particular, the inclination angle θa between the peripheral wall portion 22 and the first inclined surface 321 is set to be greater than or equal to the inclination angle θb between the peripheral wall portion 22 and the second inclined surface 322 (θa≧θb), thereby further suppressing the penetration of moisture W into the first inclined surface 321 side (the inside side of the main body case 4).

[0038] If the inclination angle θa between the peripheral wall portion 22 and the first inclined surface 321 is greater than 0°, an effect of suppressing the penetration of moisture W beyond the intersection point P32 is achieved. Therefore, the inclination angle θb between the peripheral wall portion 22 and the second inclined surface 322 may be any value. For example, the second inclined surface 322 may not be set to 0°.

[0039] 11, the bottom wall portion 31 of the cover 3 has a thickness W31 in the direction of the axis X that reaches a height position substantially equal to the tip 22a of the peripheral wall portion 22. An outer surface 31b (the lower surface in the figure) of the bottom wall portion 31 is provided with a recess 38 and a plurality of lightening holes 39. The recess 38 is formed by cutting out an area of ​​the bottom wall portion 31 that contacts the peripheral wall portion 22, and also functions as a lightening hole.

[0040] When viewed from the radial direction of the axis X, the recess 38 is provided in a range overlapping with a region on the tip 22a side of the peripheral wall 22 on the case 2 side. The recess 38 opens to the surface of the cover 3 on the lower side in the figure. In the region of the bottom wall 31 where the recess 38 is provided, the gap between the peripheral wall 22 and the bottom wall 31 (the gap in the radial direction of the axis X) is greatly expanded. Therefore, the above-mentioned capillary phenomenon does not occur in the area in contact with the recess 38 on the tip 22a side of the peripheral wall 22. Also, moisture W adhering to the outside of the main body case 4 cannot enter the gap between the peripheral wall 22 and the outer wall 32 until it fills the space between the peripheral wall 22 and the recess 38 (the area shown by hatching in the figure). This slows down the penetration of moisture W between the outer wall portion 32 (second inclined surface 322) and the peripheral wall portion 22, thereby reducing the possibility of moisture W penetrating into the gap between the first inclined surface 321 and the peripheral wall portion 22.

[0041] As described above, the groove 34 between the outer wall portion 32 and the inner wall portion 33 of the cover 3 is provided with the slit 35 that connects the inside and outside of the main body case 4 (see FIG. 10). The slit 35 is formed by cutting out the bottom wall portion 31 and the outer wall portion 32 of the cover 3, and the cut-out areas of the bottom wall portion 31 and the outer wall portion 32 form a connecting portion 37 that connects to the recess 38 described above. An upper side 372 of the connecting portion 37 in the direction of the axis X (vertical direction in the drawing) is slightly offset upward from the upper surface 31a of the bottom wall portion 31. An inclined surface 371, which is a side of the connecting portion 37 in the radial direction of the axis X (horizontal direction in the drawing), is offset toward the axis X from the recess 38 described above.

[0042] The inclined surface 371 of the connecting portion 37 is connected to the outer peripheral surface 331 of the inner wall portion 33 at the slit 35. The outer peripheral surface 331 is inclined in a direction such that the outer diameter r331 of the inner wall portion 33 becomes smaller as it moves from the slit 35 toward the tip 33a of the inner wall portion 33. An inner peripheral surface 323 of the outer wall portion 32 facing the outer peripheral surface 331 is inclined in a direction such that an inner diameter r323 of the outer wall portion 32 increases toward a tip 32a of the outer wall portion 32. Therefore, a width W34 of the groove 34 between the outer wall portion 32 and the inner wall portion 33 narrows toward the slit 35.

[0043] An intersection P35 between the outer circumferential surface 331 and the inclined surface 371 on the connecting portion 37 side is located on a straight line L35 along the opening surface of the slit 35. The inclined surface 371 is inclined such that an outer diameter r371 of the inclined surface 371 becomes smaller toward the outer surface 31b of the bottom wall portion 31. The inclined surface 371 is disposed with respect to the peripheral wall portion 22 on the case 2 side at an angle θ37.

[0044] Therefore, in the area where the slit 35 is provided in the cover 3, moisture W adhering to the lower part of the main body case 4 cannot penetrate into the slit 35 or the gap between the peripheral wall portion 22 and the outer wall portion 32 until it has filled the area of ​​the connecting portion 37. As described above, in the portion of the second inclined surface 322 of the outer wall portion 32, the gap between the peripheral wall portion 22 and the outer wall portion 32 becomes narrower toward the minimum region. Therefore, the gap on the base end 32b side of the outer wall portion 32, which is an inlet for the moisture W, becomes wider, thereby reducing the possibility of the moisture W penetrating into the gap between the peripheral wall portion 22 and the outer wall portion 32.

[0045] Furthermore, at the slit 35, the groove 34 between the outer peripheral surface 331 of the inner wall portion 33 and the inner peripheral surface 323 of the outer wall portion 32 becomes wider in width W34 as it moves away from the slit 35 toward the inside of the main body case 4. Therefore, even after the moisture W fills the inside of the communication portion 37, the moisture W is less likely to penetrate between the inner wall portion 33 and the outer wall portion 32 from the slit 35. Furthermore, the moisture W discharged from the slit 35 to the outside of the main body case 4 is also less likely to flow back from the slit 35.

[0046] FIG. 13 is a diagram illustrating the process of creating the cover 3. As shown in FIG. In this embodiment, as an example, the cover 3 is a resin part produced by injection molding using a pair of molds (a movable mold 101 and a fixed mold 102). When the movable die 101 and the fixed die 102 are joined together, a cavity C that matches the shape of the cover 3 is formed between the movable die 101 and the fixed die 102 (see FIG. 13(A): die clamping). The resin material from which the cover 3 is made is injected in a molten state into the cavity C and then solidified, thereby producing the cover 3 inside the mold (see FIG. 13(B): injection molding).

[0047] The produced cover 3 is then moved away from the fixed mold 102 (see FIG. 13(C): mold opening), and then removed from the fixed mold 102 (see FIG. 13(D): removal). Here, in order to ensure releasability when the mold is opened, a draft angle is provided on the inner periphery of the movable mold 101 and the fixed mold 102 at the peripheral portions 101a, 102a of the cavity C area, which extends to the mating surface (parting line PL: mold opening surface) between the movable mold 101 and the fixed mold 102. In this embodiment, at least a first inclined surface 321 and a second inclined surface 322 are provided on the outer periphery of the outer wall portion 32 by utilizing this draft.

[0048] 13, the peripheral edge 101a portion becomes the first inclined surface 321 of the cover 3, and the peripheral edge 102a portion becomes the second inclined surface 322 of the cover 3. The parting line PL portion becomes the intersection P32 (minimum area) between the first inclined surface 321 and the second inclined surface 322. Therefore, by changing the position of the parting line PL in the mold, it is possible to create a minimum area at a desired position on the outer periphery of the outer wall portion 32. Furthermore, by changing the draft angle in the mold (the movable mold 101 and the fixed mold 102), the first inclined surface 321 and the second inclined surface 322 can be formed at a desired angle.

[0049] Here, in the above-described embodiment, an example has been given of a case in which the minimum area (the parting line PL), which is the intersection P32 between the first inclined surface 321 and the second inclined surface 322, is located between the printed circuit board 40 and the bottom wall portion 31 in the direction of the axis X, specifically, between the printed circuit board 40 and the slit 35 (see FIG. 10). This increases the length of the gap between the first inclined surface 321 on the outer wall portion 32 side and the inner circumference of the peripheral wall portion 22 in the direction of axis X (the vertical direction in the figure), making it more difficult for moisture to penetrate into the space S1 inside the case 2. The position of the minimum area (parting line PL) can be set at any position in the direction of the axis X within a range in which the intrusion of moisture can be prevented.

[0050] In addition, a space S2 is provided between the printed circuit board 40 and the bottom wall 31. Therefore, even if moisture infiltrates into the space S2 inside the case 2 and then flows around the printed circuit board 40 and into the inside of the cover 3, the moisture can be captured in this space S2. In this embodiment, the printed circuit board 40 is located higher on the case 2 side than the inner wall 33, and a gap that communicates with the groove 34 is provided between the printed circuit board 40 and the tip 33a of the inner wall 33. Therefore, even if the amount of moisture captured inside the cover 3 increases, the groove 34 can be formed without interfering with the printed circuit board 40.

[0051] In the above embodiment, an example was given of an enlarged region provided on both one side (upper side in FIG. 10) and the other side (lower side in FIG. 10) of the minimum region in the direction of axis X. It is sufficient that the enlarged region is provided on at least one side (upper side in FIG. 10) of the minimum region. In such a case, it is possible to prevent moisture from entering.

[0052] FIG. 14 is a diagram illustrating a water ingress prevention structure 10A according to a modified example. In the above embodiment, a description has been given of the case of capillary action, in which the moisture W moves from the lower side to the upper side of the main body case 4 of the switch device 1. The capillary action also causes the moisture W to move in the horizontal direction. 14(A) and (B), case 2A is formed into a bottomed cylindrical shape by a bottom wall portion 25 and a peripheral wall portion 26 that completely surrounds the outer periphery of bottom wall portion 25. Case 2A is installed with opening 27 facing the horizontal line (left-right direction in FIG. 14(B)). In the case 2A, the printed circuit board 40 is supported on a lower region 261 of the peripheral wall portion 26 via a support stand 262. The opening of the case 2A is sealed by a cover 3A that is fitted into the opening 27 from the horizontal direction. The cover 3A is formed into a bottomed cylindrical shape by a bottom wall portion 31 that closes the opening 27 and an outer wall portion 32 that surrounds the outer periphery of the bottom wall portion all around. The outer periphery of the outer wall portion 32 is fitted into the peripheral wall portion 26 all around.

[0053] The water ingress prevention structure 10A is provided in the overlapping area where the outer wall portion 32 and the peripheral wall portion 26 overlap. As shown in (B) of Figure 14, the outer periphery of the outer wall portion 32 is provided with a first inclined surface 321 in which the outer diameter r321 of the outer wall portion 32 becomes smaller toward the tip end 32a, and a second inclined surface 322 in which the outer diameter r322 becomes smaller toward the base end 32b. An intersection P32 between the first inclined surface 321 and the second inclined surface 322 is a minimum area where the gap between the outer wall portion 32 and the peripheral wall portion 26 on the case 2 side is minimum. Between the peripheral wall portion 26 and the outer wall portion 32, enlarged regions are provided on one side (the tip end 32a side) and the other side (the base end 32b) of the minimum region in the direction of the axis X, where the gap between the peripheral wall portion 26 and the outer wall portion 32 is wider than the minimum region. In the enlarged region on the tip 32a side, the gap between the peripheral wall portion 26 and the outer wall portion 32 becomes wider from the intersection point P32 toward the tip 32a. In the enlarged region on the base end 32b side, the gap between the peripheral wall portion 26 and the outer wall portion 32 becomes wider from the intersection point P32 toward the base end 32b.

[0054] Such water ingress prevention structure 10A also widens the gap on the base end 32b side of outer wall 32, which is the ingress point for moisture W, thereby reducing the possibility of ingress of moisture W. Furthermore, the gap between peripheral wall 26 and outer wall 32 narrows toward the inside of main body case 4 (the tip 32a side of outer wall 32), so that if dust or the like ingresses from the base end 32b side, the ingressing dust or the like is less likely to reach intersection P32, which is the smallest area. In addition, in the portion of the first inclined surface 321, the gap between the peripheral wall portion 26 and the outer wall portion 32 becomes wider as it moves away from the minimum region toward the tip 32a. The suction force due to the capillary phenomenon becomes weaker in the gap that becomes wider as it moves further. The intersection point P32, which is the minimum region, is provided along the outer periphery of the outer wall portion 32 over the entire circumferential direction.

[0055] Therefore, the moisture W that penetrates into the gap between the peripheral wall portion 26 and the outer wall portion 32 from the second inclined surface 322 side and reaches the intersection point P32, which is the minimum area, moves in the circumferential direction along the minimum area more easily than moving in a direction that penetrates beyond the intersection point P32 toward the first inclined surface 321. Therefore, the moisture W that reaches the intersection point P32 is less likely to penetrate beyond the intersection point P32 toward the first inclined surface 321. In particular, the inclination angle θa between the peripheral wall portion 26 and the first inclined surface 321 is set to be equal to or larger than the inclination angle θb between the peripheral wall portion 26 and the second inclined surface 322 (θa≧θb), which further suppresses the intrusion of moisture W into the first inclined surface 321. In addition, in the case of the present water intrusion prevention structure 10A, the minimum area is provided along the vertical direction, so that the moisture W naturally moves downward below the printed circuit board 40 due to gravity.

[0056] 15 and 16 are diagrams illustrating a water ingress prevention structure according to a modified example. 15 and 16, the area in which the water ingress prevention structure 10 is provided is indicated by an imaginary line Im. In the above embodiment, a case has been illustrated in which the minimum area constituting the water ingress prevention structure 10 is provided around the entire periphery in the overlapping area where the cylindrical peripheral wall portion 22 and the cylindrical outer wall portion 32 overlap. The minimum area constituting the water ingress prevention structure 10 does not necessarily have to be provided around the entire periphery. For example, as shown in Fig. 15, a minimum area constituting the water-ingress prevention structure 10 may be provided only in a specific area where it is particularly desired to prevent water ingress. With this configuration, it is possible to prevent water from ingressing from the area where the water-ingress prevention structure 10 is provided.

[0057] For example, as shown in Fig. 16, the range of the minimum area may be set in an area of ​​the cover 3A located to the side of the printed circuit board 40 so as to cross the area in which the printed circuit board 40 is provided. In Fig. 16, the minimum area is provided in the area indicated by the imaginary line Im, and it is possible to prevent the infiltration of only the moisture W that has infiltrated from the end face on the right side of the figure by capillary action within the range that can directly reach the printed circuit board 40.

[0058] In the above embodiment, the minimum area constituting the water ingress prevention structure 10 is provided in the overlapping area where the cylindrical peripheral wall portion 22 and the cylindrical outer wall portion 32 overlap, but the minimum area constituting the water ingress prevention structure 10 may be provided only in the area where two plate-like wall portions overlap. Therefore, for example, in the case where a main body case 4 is used in which the outer wall portion 32 of the cover 3 is provided with a gap in the circumferential direction, for example, two inclined surfaces may be provided on the outer periphery of the outer wall portion 32 to provide a minimum area in which the gap with the peripheral wall portion 22 is minimized.

[0059] As described above, the water ingress prevention structure 10 according to the embodiment has the following configuration. (1) A case 2 (first housing) having a peripheral wall portion 22 (wall portion) along the axis X direction; The cover 3 (second housing) is assembled to the case 2 from the direction of the axis X along the opening direction of the peripheral wall portion 22, and has an outer wall portion 32 (insertion wall) inserted into the peripheral wall portion 22 from the direction of the axis X. When viewed radially about axis X, in the overlap region where peripheral wall portion 22 and outer wall portion 32 overlap, there is a minimum region where the gap between peripheral wall portion 22 and outer wall portion 32 is smallest, and on at least one side of the minimum region in the direction of axis X, there is an expanded region where the gap between peripheral wall portion 22 and outer wall portion 32 is wider than the minimum region, and one side of the minimum region is connected to the inside of case 2.

[0060] Between the peripheral wall portion 22 of the case 2 and the outer wall portion 32 of the cover 3, there exists a small gap through which capillary action can occur. With the above-described configuration, moisture W that has penetrated into the gap due to capillary action can reach the minimum area, but since the gap between the peripheral wall portion 22 and the outer wall portion 32 is wider on the tip 32a side of the outer wall portion 32 than the minimum area, it is possible to preferably prevent moisture W from penetrating beyond the minimum area.

[0061] (2) In (1) above, The enlarged regions are provided on one side and the other side of the minimum region in the direction of the axis X.

[0062] With this configuration, the possibility of moisture, dust, and the like entering the inside of the case 2 can be reduced.

[0063] (3) In (2) above, In the expanded region located on one side of the minimum region, the gap between the peripheral wall portion 22 and the outer wall portion 32 becomes wider as the distance from the minimum region to that side increases. In the expanded region located on the other side as viewed from the minimum region, the gap between the peripheral wall portion 22 and the outer wall portion 32 becomes wider as the distance from the minimum region to the other side increases.

[0064] With this configuration, moisture W that has penetrated into the gap due to capillary action can reach the minimum area, but since the gap between the peripheral wall portion 22 and the outer wall portion 32 is wider on the tip 32a side of the outer wall portion 32 than the minimum area, it is possible to effectively prevent moisture W from penetrating beyond the minimum area.

[0065] (4) In any one of (1) to (3) above, The peripheral wall portion 22 has a cylindrical shape when viewed from the axis X direction. The outer wall portion 32 has a cylindrical shape and is inserted into the inner periphery of the peripheral wall portion 22 over the entire periphery. The outer periphery of the outer wall portion 32 is a first inclined surface 321 in which the outer diameter of the outer wall portion 32 becomes smaller from the base end 32b side of the outer wall portion 32 toward the tip end 32a side; A second inclined surface 322 is provided in such a direction that the outer diameter of the outer wall portion 32 becomes smaller from the tip end 32a side of the outer wall portion 32 toward the base end 32b side. The boundary between the first inclined surface 321 and the second inclined surface 322 is the minimum area.

[0066] With this configuration, in the portion of the second inclined surface 322, the gap between the peripheral wall portion 22 and the outer wall portion 32 becomes wider as it moves away from the minimum area. This widens the gap on the base end 32b side of the outer wall portion 32, which is the inlet for moisture W, reducing the possibility of moisture W intrusion. Furthermore, because the gap between the peripheral wall portion 22 and the outer wall portion 32 becomes narrower toward the inside of the main body case 4 (the tip 32a side of the outer wall portion 32), if dust or the like intrudes from the base end 32b side, the intruded dust or the like is less likely to reach the intersection point P32, which is the minimum area.

[0067] (I) In paragraph (4) above: An inclination angle θa of the first inclined surface 321 with respect to the inner circumference of the peripheral wall portion 22 is larger than an inclination angle θb of the second inclined surface 322 with respect to the inner circumference of the peripheral wall portion 22 .

[0068] Since the second inclined surface 322 is located further outward from the main case 4 than the first inclined surface 321, the moisture W penetrates into the gap between the second inclined surface 322 and the peripheral wall portion 22 first. With the above configuration, the gap between the second inclined surface 322 and the peripheral wall portion 22 becomes wider toward the outside of the main body case 4, so that it is possible to suppress the intrusion of moisture W into the gap. Even if moisture W infiltrates into the gap between the second inclined surface 322 and the peripheral wall portion 22, a large amount of moisture W can be captured in the gap between the second inclined surface 322 and the peripheral wall portion 22, so that it is possible to reduce the possibility that moisture W will infiltrate beyond the minimum area into the gap between the first inclined surface 321 and the peripheral wall portion 22.

[0069] (5) In (4) above, The minimum area is provided around the entire outer periphery of the outer wall portion 32 .

[0070] Moisture W that penetrates into the gap between the second inclined surface 322 and the peripheral wall portion 22 and reaches the minimum area can more easily move circumferentially through the gap between the second inclined surface 322 and the peripheral wall portion 22 than it can move beyond the minimum area between the first inclined surface 321 and the peripheral wall portion 22 toward the first inclined surface 321. Therefore, with the above-mentioned configuration, the infiltrated moisture W is unlikely to infiltrate into the gap between the first inclined surface 321 and the peripheral wall portion 22 until the gap between the second inclined surface 322 and the peripheral wall portion 22 is filled over the entire circumference. This reduces the possibility that the moisture W will infiltrate into the gap between the first inclined surface 321 and the peripheral wall portion 22 beyond the minimum area.

[0071] (II) In (5) above, The cover 3 is a resin part produced by injection molding using a pair of molds. The minimum area exists in a position corresponding to a parting line PL that appears on the outer wall portion 32 at the mating surfaces of a pair of molds.

[0072] With this configuration, the minimum area can be set at a desired position in the direction of the axis X simply by shifting the position of the parting line PL.

[0073] (6) In (5) above, In the cover 3, an outer wall portion 32 is provided on the periphery of a bottom wall portion 31 (lid portion) that closes the opening of the peripheral wall portion 22. In the overlapping region as viewed from the radial direction of the axis X, a recess 38 recessed in a direction away from the peripheral wall 22 on the case 2 side is provided in the region of the bottom wall 31.

[0074] With this configuration, moisture W adhering to the main body case 4 can be captured in the recess 38 before it penetrates between the second inclined surface 322 and the peripheral wall portion 22. This makes it possible to slow down the penetration of moisture W between the second inclined surface 322 and the peripheral wall portion 22, thereby reducing the possibility of moisture W penetrating into the gap between the first inclined surface 321 and the peripheral wall portion 22.

[0075] (III) In (6) above, When viewed from the direction of the axis X, the recesses 38 are provided at a plurality of locations on the peripheral wall portion 22 at intervals in the circumferential direction.

[0076] With this configuration, no matter where moisture W adheres to in the circumferential direction inside the main body case 4, the adhered moisture W can be captured in the recess 38. This can delay the intrusion of moisture W between the second inclined surface 322 and the peripheral wall portion 22, thereby reducing the possibility of moisture W penetrating into the gap between the first inclined surface 321 and the peripheral wall portion 22.

[0077] (7) In (5) or (6) above, A cylindrical inner wall portion 33 is provided inside the outer wall portion 32. The inner wall portion 33 is provided with a gap between it and an inner circumferential surface 323 of the outer wall portion 32 . A slit 35 penetrating the bottom wall 31 is provided in the area between the outer wall 32 and the inner wall 33 in the bottom wall 31 , and oriented along the inner wall 33 .

[0078] With this configuration, moisture W that has entered the inside of the main body case 4 can be discharged to the outside through the slits 35, reducing the possibility that moisture W will adhere to electronic components placed inside the main body case 4.

[0079] (8) In (7) above, The slit 35 opens into the recess 38 . In a cross-sectional view taken along the axis X, an inner peripheral surface 323 of the outer wall portion 32 and an outer peripheral surface 331 of the inner wall portion 33 are inclined in such a way that they approach each other toward the opening of the slit .

[0080] With this configuration, in the portion of the slit 35, the groove 34 between the outer peripheral surface 331 of the inner wall portion 33 and the inner peripheral surface 323 of the outer wall portion 32 becomes wider in width W34 as it moves away from the slit 35 toward the inside of the main body case 4. This makes it difficult for moisture W to penetrate between the inner wall portion 33 and the outer wall portion 32 from the slit 35. Furthermore, the moisture W discharged from the portion of the slit 35 to the outside of the main body case 4 is also difficult to flow back from the portion of the slit 35. The possibility that moisture W in the recess 38 will penetrate into the inside of the main case 4 through the slits 35 can be reduced.

[0081] (IV) In (8) above, In the case 2, a communication portion 37 that communicates between the slit 35 and the recess 38 is provided by cutting out a portion of the outer wall portion 32 and the bottom wall portion 31. In a cross-sectional view along the axis X, the inner periphery of the peripheral wall portion 22 and an inclined surface 731 which is an opposing surface of the peripheral wall portion 22 at the communication portion 37 are inclined in directions approaching each other toward the opening of the slit .

[0082] With this configuration, moisture W adhering to the main body case 4 can be captured in the space between the connecting portion 37 and the recess 38, thereby slowing down the penetration of moisture into the gap between the peripheral wall portion 22 and the second inclined surface 322.

[0083] (V) In (8) above, When viewed from the direction of the axis X, the slits 35 are provided at a plurality of locations at intervals in the circumferential direction of the peripheral wall portion 22.

[0084] With this configuration, moisture W that has entered the inside of the main body case 4 can be discharged to the outside through the slits 35, reducing the possibility that moisture W will adhere to electronic components placed inside the main body case 4.

[0085] Although the embodiment and modified examples of the present invention have been described above, the present invention is not limited to these and can be modified as appropriate within the scope of the technical concept of the invention. For example, the present invention is not limited to being applied to a switch device as in the above embodiment, but can be applied to devices that have electronic components and require waterproofing. For example, the present invention can be applied to various control devices, connectors, etc. [Explanation of symbols]

[0086] 1: Switch device 2, 2A: Case 22: Peripheral wall (wall) 22a: Tip 25: Bottom wall 26: Peripheral wall part 27 :Aperture 3, 3A: Cover 31: Bottom wall (lid) 32: External wall part 32a: Tip 32b: Proximal end 321: 1st slope 322:Second slope 323: Inner peripheral surface 33: Inner wall 33a:Tip 331: Outer surface 34: Groove 35: Slit 37: Liaison Department 371: Inclined surface 38: Recess 4: Main body case 40: Printed circuit board 5(5A~5D): Switch 8: Cover material 81: Base 82: Placement section 83: Storage unit 84: Side wall 84a: Bottom edge 10, 10A: Water ingress prevention structure W: Moisture X: Axis line

Claims

1. A first housing having a wall portion along an axial direction; a second housing that is assembled to the first housing from the axial direction and includes an insertion wall that is inserted into the wall portion from the axial direction, A water ingress prevention structure in which, when viewed from the radial direction of the axis, in an overlap region where the wall portion and the insertion wall overlap, there is a minimum region where the gap between the wall portion and the insertion wall is smallest, and on at least one side of the minimum region in the axial direction, an expanded region is provided in which the gap between the wall portion and the insertion wall is wider than the minimum region, and the one side viewed from the minimum region is connected to the inside of the first housing.

2. In claim 1, A water ingress prevention structure, wherein the enlarged areas are provided on one side and the other side of the minimum area in the axial direction.

3. In claim 2, In the enlarged region located on the one side as viewed from the minimum region, the gap between the wall portion and the insertion wall becomes wider as the gap moves away from the minimum region to the one side, A water ingress prevention structure, in which, in an expanded region located on the other side as viewed from the minimum region, the gap between the wall portion and the insertion wall becomes wider as the distance from the minimum region to the other side increases.

4. In claim 3, The wall portion has a cylindrical shape when viewed from the axial direction, The insertion wall has a cylindrical shape that is inserted into the inner periphery of the wall portion over the entire periphery, The outer periphery of the insertion wall is A first inclined surface in which the outer diameter of the insertion wall decreases from the base end side to the tip end side of the insertion wall; A second inclined surface is provided in such a manner that the outer diameter of the insertion wall becomes smaller from the tip side to the base end side of the insertion wall, A water ingress prevention structure, wherein the boundary between the first inclined surface and the second inclined surface is the minimum area.

5. In claim 4, A water ingress prevention structure, wherein the minimum area is provided around the entire outer periphery of the insertion wall.

6. In claim 5, In the second housing, the insertion wall is provided on a peripheral portion of a lid portion that closes the opening of the wall portion, A water ingress prevention structure in which, in the overlapping region when viewed radially from the axis, a recess is provided in the area of ​​the lid portion that is recessed in a direction away from the wall portion on the first housing side.

7. In claim 6, A cylindrical inner wall portion is provided on the inside of the insertion wall, The inner wall portion is provided with a gap between it and an inner periphery of the insertion wall, A water ingress prevention structure, in which a through hole penetrating the lid portion is provided in the area between the wall portion and the inner wall portion of the lid portion, oriented along the inner wall portion.

8. In claim 7, The through hole opens into the recess, A water ingress prevention structure, in which, when viewed in a cross section along the axial direction, the inner circumference of the insertion wall and the outer circumference of the inner wall portion are inclined in a direction approaching each other as they approach the opening of the through hole.

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