JP4289325B2 - Enclosure for electronic devices - Google Patents

Description

  The present invention relates to an electronic device casing.

  Conventionally, there has been one disclosed in Patent Document 1 for preventing moisture from entering into a housing for an electronic device.

  The electronic device casing shown in Patent Document 1 includes a casing main body and a lid, and the like, between the casing main body and the lid, between the casing main body and the connector, and between the lid and the connector. Is provided with a waterproof packing.

Moreover, in order to prevent the dew condensation to an electronic device, as shown in patent document 2, there existed some which covered an electronic device with a moisture-proof agent.
JP 2000-244142 A JP-A-5-343817

  However, in the case of the electronic device casing shown in Patent Document 1, since the packing is provided, there is a problem that the cost increases by the amount of the packing. Also, with respect to Patent Document 2, since a moistureproof agent is provided, there is a problem that the cost increases by the amount of the moistureproof agent.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electronic device casing that can prevent the occurrence of condensation on the electronic device in the casing while suppressing cost.

In order to achieve the above object, an electronic device casing according to claim 1 is provided with a circuit board on which a circuit element is mounted, and an external connection unit that electrically connects the circuit board and the outside. An opening for exposing at least a part of the external connection portion to the outside, and a position corresponding to the opening side end portion of the mounting area where the circuit element is mounted on the circuit board. at least a portion between the opening and projects into at least one, or the direction of the circuit board in at least one of substantially parallel case inside surface of the substantially vertical housing surface to the mounting surface of the circuit elements in the circuit board Provided with an air intrusion prevention wall that lowers the humidity of the air by lowering the temperature of the air that enters, and prevents the ingress of air in a high humidity and high temperature state , Electronic device housing Wherein in a state attached to a subject with, at least one of the surface substantially perpendicular to the mounting surface of the circuit elements in the circuit board, or the inclination shape and be Rukoto inclined to the direction of gravity as substantially toward at least one of the parallel surfaces It is what.

In this way, an air intrusion prevention wall that protrudes in the direction of the circuit board is provided at least at a portion between the opening and the position corresponding to the opening side end of the mounting area in which the circuit element is mounted on the circuit board. As a result, the flow resistance of air in the housing for electronic devices can be increased to reduce the entry and exit of air in the case. In addition, by providing an air ingress prevention wall, it is possible to lengthen the air ingress path to the circuit board or circuit element in the electronic device casing, so the temperature of the air entering the electronic device casing can be reduced. It is possible to reduce the humidity of the air entering the electronic device casing by reducing the air ingress prevention wall. Therefore, since it is possible to prevent the occurrence of condensation on the circuit board and circuit elements in the case without using a moisture-proofing agent or packing, it is possible to prevent the occurrence of condensation on the electronic device in the case while reducing costs. Can do. In addition, the air intrusion prevention wall has an inclined shape that inclines in the direction of gravity toward the at least one of the surfaces substantially perpendicular to the circuit board in a state in which the housing for the electronic device is attached to the attachment target. It is possible to prevent water droplets adhering to the ingress prevention wall from dripping onto the circuit board or the like.

In addition, as shown in claim 2 , the air intrusion prevention wall is preferably provided from one end to the other end on a plane substantially parallel to the circuit board.

Further, as shown in claim 3, when a plurality of air intrusion prevention walls are provided on a surface substantially parallel to the circuit board, the air flow resistance in the electronic device casing is further increased, and the air inflow in the electronic device casing is increased. It is possible to reduce the entry and exit and further prevent the occurrence of dew condensation on the circuit board and the circuit element in the electronic device casing.

Further, as shown in claim 4, it is preferable that the air intrusion prevention wall is provided from one end portion to the other end portion in a plane substantially perpendicular to the circuit board.

Further, since the operation and effect of the electronic device casing according to claim 5 are the same as the operation and effect according to claim 3 , the description thereof is omitted.

According to a sixth aspect of the present invention, there is provided a housing for an electronic device comprising a water discharge portion that discharges water droplets adhering to the inner peripheral portion to the outside.

Even when water droplets adhere to the inner peripheral portion of the electronic device casing, as shown in claim 6 , the water droplets are provided by providing a water discharge portion that discharges water droplets attached to the inner peripheral portion to the outside. Can be prevented from adhering to the electronic device.

The electronic device casing according to claim 7 is characterized in that the water discharge portion is provided at a position to be a bottom portion in a state in which the electronic device casing is attached to an attachment target. .

  As described above, it is preferable that the water discharge portion is provided at a position which becomes a bottom portion in a state where the electronic device casing is attached to the attachment target, because water droplets are more easily discharged to the outside.

In the electronic device casing according to claim 8 , the water discharge portion includes an entry preventing portion that prevents entry of liquid from the outside.

  In this way, by providing the entry preventing unit that prevents the entry of liquid from the outside, it is possible to further prevent the occurrence of condensation on the electronic device in the electronic device casing.

In addition, as shown in claim 9 , the intrusion prevention unit includes a hydrophobic fiber formed in a direction from the inner periphery of the water discharge unit toward the central axis of the water discharge unit, and the hydrophobic fiber is formed of the water discharge unit. From the inner peripheral part to the central axis of the water discharge part, it can be directed outward.

Further, as shown in claim 10 , the hydrophobic fiber is preferably any one of polypropylene, polyacetal, and polyethylene. In addition, as shown in claim 11 , the water discharge portion may be a separate member from the electronic device casing.

Further, as shown in claims 12 to 14 , the material of the housing for the electronic device can be a resin material, aluminum, or iron.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view before assembly showing a schematic configuration of the ECU 100 according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view after assembly showing a schematic configuration of ECU 100 in the first embodiment of the present invention. FIG. 3 is a perspective view showing a schematic configuration of the upper member 10 in the first embodiment of the present invention. FIG. 4 is a cross-sectional view illustrating the air ingress of ECU 100 in the first embodiment of the present invention. In the present embodiment, description will be made using an example in which an electronic device casing (hereinafter also referred to as a case) is applied to an ECU (Electric Control Unit).

  As shown in FIG. 1, the ECU 100 includes an upper member 10 and a lower member 12 that constitute a case, a circuit board 20 that constitutes an electronic device 200, a circuit element 21, a connector 22, a terminal 23, and the like. The ECU 100 is mounted, for example, between a dash panel in an engine room and an engine and fixed with brackets and bolts.

  As shown in FIG. 3, the upper member 10 constituting the case has a substantially box shape opened to accommodate the electronic device 200, and an opening that exposes at least a part of the connector 22 to the outside, into the case. An air intrusion prevention wall 11 for reducing the ingress of air containing water is provided. The air intrusion prevention wall 11 will be described in detail later. The lower member 12 constituting the case is a lid member having a substantially rectangular plate shape with a shallow bottom that closes the open surface of the upper member 10.

  The upper member 10 and the lower member 12 are made of, for example, aluminum, resin, iron, or the like, and can be manufactured by aluminum die casting, resin molding, pressing, or the like. Here, the manufacturing method by aluminum die-casting is demonstrated as an example of the manufacturing method of the upper member 10 and the lower member 12. FIG. The aluminum die casting apparatus includes a mold (a fixed mold and a movable mold), a push rod, a sleeve, a plunger, a cavity, and the like.

  When molding the upper member 10 and the lower member 12 with such an aluminum die cast molding apparatus, first, the movable mold is operated, and the mold is closed to a mold clamping state. In this state, a release agent is supplied into the cavity, and the release agent is adhered to the inner surface of the cavity. Thereafter, by driving the plunger with the mold temperature adjusted to a predetermined temperature, the molten metal in the sleeve is injected at a predetermined injection speed (for example, about 10 to 60 m / s) through a gate provided in the mold. Then, it is supplied into the cavity at a predetermined casting pressure (for example, about 50 to 100 MPs). When the molten metal in the cavity is solidified, the movable mold is moved to open the mold. Furthermore, the molded products (upper member 10 and lower member 12) are released from the mold by extruding the molded products (upper member 10 and lower member 12) formed by push rods.

  The electronic device 200 includes a circuit board 20, a circuit element 21, a connector 22, a terminal 23, and the like. The circuit board 20 is a board on which a wiring pattern (not shown) and via holes for connecting the wiring patterns are formed. On the circuit board 20, circuit elements 21 such as a microcomputer, a power transistor, a resistor, and a capacitor are mounted. Further, the circuit board 20 is electrically and mechanically connected with a connector 22 and a terminal 23 as external connection portions for electrical connection with the outside. The terminal 23 is electrically connected to the circuit element 21 via a wiring pattern formed on the circuit board 20.

  The electronic device 200 is fixed to the lower member 12 with, for example, a screw (not shown). And the electronic device 200 is accommodated in a case as shown in FIG. 2 by fastening the upper member 10 and the lower member 12 with a screw etc. which are not shown in figure, for example.

  When the upper member 10 and the lower member 12 are assembled in this way, a gap may occur between the upper member 10 and the connector 22 due to assembly tolerances. If a gap is generated between the upper member 10 and the connector 22, air containing moisture may enter the case from the gap. Further, when air containing moisture enters the case, condensation may occur in the electronic device 200. If dew condensation occurs on the electronic device 200, particularly the circuit board 20 or the circuit element 21, it may cause a malfunction such as a short circuit or corrosion.

  Therefore, the present invention includes an air intrusion prevention wall 11 in order to reduce the ingress of moisture-containing air into the case and prevent the electronic device 100 from causing condensation.

  Here, the air intrusion prevention wall 11 which is a characteristic part of the present invention will be described. As shown in FIGS. 1 to 3, the air intrusion prevention wall 11 is provided from one end portion to the other end portion in a plane substantially parallel to the circuit board 20 of the upper member 10. The air intrusion prevention wall 11 is at least a part between the position corresponding to the opening side end of the mounting region on the circuit board 20 of the upper member 10 where the circuit element 21 is mounted and the opening of the upper member 10. And it is provided so as to protrude in the direction of the circuit board 20. In addition, although the one where the clearance gap between the air intrusion prevention wall 11 and the electronic device 200 is smaller is preferable, when the assembly tolerance of the upper member 10, the lower member 12, and the connector 22 is considered, about 0.5-3 mm is preferable.

  When the electronic device 200 includes the terminal 23 that electrically connects the circuit board 20 and the connector 22, the air intrusion prevention wall 11 has a length and a shape that do not contact the terminal 23. Further, in the present embodiment, the air intrusion prevention wall 11 has been described using an example in which the air ingress prevention wall 11 is provided from one end portion to the other end portion in a plane substantially parallel to the circuit board 20 of the upper member 10. Is not limited to this, and may be provided at a position corresponding to a gap formed between the upper member 10 and the connector 22.

  As a result of comparing (simulating) the case where the air ingress prevention wall 11 is installed with the case where the air ingress prevention wall 11 is not installed under the condition that the differential pressure between the inside of the case and the outside is equal, the flow rate flowing into the case is The air resistance of 11 was able to reduce by 30%.

  In addition, as a result of comparing (simulating) the case where the air intrusion prevention wall 11 is not installed and the case where it is not installed under the condition that the differential pressure between the inside of the case and the outside is equal, as a result of the air flowing into the inside from the outside of the case Since the contact area could be increased by 30%, the thermal conductivity (W / ° C.) could be increased by 30%.

  In addition, as a result of comparing (simulating) the temperature difference between the air entering the case (external air temperature) and the case internal (internal air temperature) when the air intrusion prevention wall 11 is installed and not installed, the external air It has been found that when the temperature difference between the temperature and the internal air temperature is 30 ° C., there is an effect of reducing the temperature difference between the external air temperature and the internal air temperature by 2 ° C.

  Thus, by providing the air intrusion prevention wall 11 in the case (upper member 10), the flow resistance of air in the case is increased to reduce the flow of air in the case, and the circuit board 20 and circuit elements in the case are reduced. It is possible to prevent the occurrence of condensation on 21.

  Further, by providing the case (upper member 10) with the air entry preventing wall 11, the air entry path has a labyrinth structure as shown in FIG. That is, since the air entry path to the circuit board 20 and the circuit element 21 in the case can be lengthened, the temperature of the air entering the case is lowered by the air intrusion prevention wall 11 to enter the case. The humidity of the incoming air can be reduced. Therefore, it is possible to prevent the occurrence of condensation on the circuit board 20 and the circuit element 21 in the case.

  For example, when the ECU 100 is applied to an engine control device, there is a possibility that air of high humidity and high temperature (temperature higher than the temperature in the ECU 100) enters the case. In such a case, the air ingress prevention wall 11 can reduce the temperature of the high-humidity and high-temperature air, and the air humidity can be reduced.

  Thus, by providing the air intrusion prevention wall 11 on a surface substantially parallel to the circuit board 20 of the case (upper member 10), the circuit board 20 and the circuit element 21 in the case can be connected without using a moisture-proofing agent or packing. Since the occurrence of condensation can be prevented, the occurrence of condensation on the electronic device 200 in the case can be prevented while suppressing costs.

(Modification 1)
In the above-described embodiment, the air intrusion prevention wall 11 has been described using an example in which the upper member 10 is provided on a surface substantially parallel to the circuit board 20. However, the present invention is not limited to this.

  The air intrusion prevention wall 11 in Modification 1 will be described. FIG. 5 is a cross-sectional view showing a schematic configuration of ECU 100 of Modification 1 according to the first embodiment of the present invention. FIG. 6 is a perspective view showing a schematic configuration of the lower member 12 of Modification 1 according to the first embodiment of the present invention. Note that the ECU 100 in the first modification is often in common with that according to the above-described embodiment, and therefore, detailed description of common parts will be omitted, and different parts will be described mainly. In the first modification, the difference from the first embodiment described above is the installation position of the air intrusion prevention wall 11.

  When the upper member 10 and the lower member 12 are assembled as described above, there may be a gap between the lower member 12 and the connector 22 due to assembly tolerances. Even when a gap is generated between the lower member 12 and the connector 22, there is a possibility that air containing moisture may enter the case from the gap. Further, when air containing moisture enters the case, condensation may occur in the electronic device 200. If dew condensation occurs on the electronic device 200, particularly the circuit board 20 or the circuit element 21, it may cause a malfunction such as a short circuit or corrosion.

  Therefore, as shown in FIGS. 5 and 6, the air intrusion prevention wall 11 in Modification 1 is provided from one end to the other end of the surface of the lower member 12 substantially parallel to the circuit board 20. In addition, the air intrusion prevention wall 11 is at least a part between the position corresponding to the opening side end of the mounting region where the circuit element 21 is mounted on the circuit board 20 of the lower member 12 and the opening of the lower member 12. And it is provided so as to protrude in the direction of the circuit board 20. In addition, although the one where the clearance gap between the air intrusion prevention wall 11 and the electronic device 200 is smaller is preferable, when the assembly tolerance of the upper member 10, the lower member 12, and the connector 22 is considered, about 0.5-3 mm is preferable.

  When the electronic device 200 includes the terminal 23 that electrically connects the circuit board 20 and the connector 22, the air intrusion prevention wall 11 has a length that does not contact the terminal 23. Further, in the present embodiment, the air intrusion prevention wall 11 has been described using an example in which the lower member 12 is provided from one end to the other end on a surface substantially parallel to the circuit board 20. Is not limited to this, and may be provided at a position corresponding to a gap formed between the lower member 12 and the connector 22.

  In the present embodiment, the lower member 12 having a substantially rectangular plate shape with a shallow bottom has been described as an example. However, the present invention is not limited to this, and the electronic device is similar to the upper member 10. It is good also as the substantially box shape open | released in order to accommodate 200. FIG. In this case, the air intrusion prevention wall 11 is not limited to the one provided on the surface substantially parallel to the circuit board 20 of the lower member 12, but the lower member 12 such as a surface substantially perpendicular to the circuit board 20 of the lower member 12. What is necessary is just to provide in the position corresponding to the clearance gap produced between the connector 22 and the connector 22.

  Thus, by providing the air ingress prevention wall 11 on the lower member 12, it is possible to prevent the occurrence of condensation on the circuit board 20 and the circuit element 21 in the case without using a moisture-proofing agent or packing. Generation | occurrence | production of the dew condensation to the electronic device 200 in a case can be prevented, suppressing cost.

(Modification 2)
In the above-described embodiment, the air intrusion prevention wall 11 has been described using an example in which the upper member 10 or the lower member 12 is provided on a surface substantially parallel to the circuit board 20, but the present invention is limited to this. It is not a thing.

  The air intrusion prevention wall 11 in Modification 2 will be described. FIG. 7 is a cross-sectional view showing a schematic configuration of ECU 100 of Modification 2 according to the first embodiment of the present invention. FIG. 8 is a perspective view showing a schematic configuration of the upper member 10 of Modification 2 according to the first embodiment of the present invention. The ECU 100 in the second modification is often in common with that in the first embodiment and the first modification described above, and therefore, detailed description of common parts will be omitted and different parts will be described mainly. . In the second modification, the difference from the first embodiment and the first modification described above is the installation position of the air intrusion prevention wall 11.

  When the upper member 10 and the lower member 12 are assembled as described above, a gap may be generated due to an assembly tolerance between the side surface of the upper member 10 and the connector 22. Even when a gap is generated between the side surface of the upper member 10 and the connector 22, air containing moisture may enter the case from the gap. Further, when air containing moisture enters the case, condensation may occur in the electronic device 200. If dew condensation occurs on the electronic device 200, particularly the circuit board 20 or the circuit element 21, it may cause a malfunction such as a short circuit or corrosion.

  Therefore, as shown in FIGS. 7 and 8, the air intrusion prevention wall 11 in Modification 2 is provided from one end to the other end of the surface of the upper member 10 that is substantially perpendicular to the circuit board 20. The air intrusion prevention wall 11 is at least a part between the position corresponding to the opening side end of the mounting region on the circuit board 20 of the upper member 10 where the circuit element 21 is mounted and the opening of the upper member 10. And it is provided so as to protrude in the direction of the circuit board 20. In addition, although the one where the clearance gap between the air intrusion prevention wall 11 and the electronic device 200 is smaller is preferable, when the assembly tolerance of the upper member 10, the lower member 12, and the connector 22 is considered, about 0.5-3 mm is preferable.

  When the electronic device 200 includes the terminal 23 that electrically connects the circuit board 20 and the connector 22, the air intrusion prevention wall 11 has a length that does not contact the terminal 23. Further, in the present embodiment, the air intrusion prevention wall 11 has been described using an example in which the upper member 10 is provided from one end portion to the other end portion on a surface substantially perpendicular to the circuit board 20. Is not limited to this, and may be provided at a position corresponding to a gap formed between the upper member 10 and the connector 22.

  Thus, by providing the air ingress prevention wall 11 on the side surface of the upper member 10, it is possible to prevent the occurrence of condensation on the circuit board 20 and the circuit element 21 in the case without using a moisture-proofing agent or packing. Therefore, it is possible to prevent the occurrence of condensation on the electronic device 200 in the case while suppressing the cost.

(Modification 3)
In the above-described embodiment, the description has been given using the example in which one air intrusion prevention wall 11 is provided on the upper member 10 or the lower member 12, but the present invention is not limited to this.

  The air intrusion prevention wall 11 in Modification 3 will be described. FIG. 9 is a cross-sectional view for explaining an air intrusion prevention wall 11 of Modification 3 according to the first embodiment of the present invention, where (a) is a case where it is formed on the upper surface of the upper member 10, and (b) ) Is formed on the side surface of the upper member 10, and (c) is formed on the bottom surface of the lower member 12. Note that the ECU 100 in the third modification is often the same as that in the first embodiment, the first modification, and the second modification, and therefore, detailed description of common parts will be omitted below, and different parts will be emphasized. I will explain it. The third modification differs from the first embodiment and the first modification and the second modification described above in the number of air intrusion prevention walls 11.

  As shown in FIG. 9, a plurality of air intrusion prevention walls 11 in Modification 3 are provided on the upper member 10 or the lower member 12. That is, when the air intrusion prevention wall 11 is provided on the upper member 10, a plurality of air intrusion prevention walls 11 may be provided on a surface substantially parallel to the circuit board 20 of the upper member 10 as shown in FIG. Further, as shown in FIG. 9B, a plurality of air intrusion prevention walls 11 may be provided on a surface substantially perpendicular to the circuit board 20 of the upper member 10. Further, as shown in FIG. 9C, when the air intrusion prevention wall 11 is provided on the lower member 12, a plurality of air intrusion prevention walls 11 may be provided on a surface substantially parallel to the circuit board 20 of the lower member 12.

  In this way, by providing a plurality of air intrusion prevention walls 11 on the upper member 10 or the lower member 12, the flow resistance of the air in the case is further increased to reduce the flow of air in the case, and the circuit in the case is reduced. The occurrence of condensation on the substrate 20 and the circuit element 21 can be further prevented.

(Modification 4)
The air intrusion prevention wall 11 in Modification 4 will be described. FIG. 10 is a diagram for explaining an air intrusion prevention wall 11 according to Modification 4 of the first embodiment of the present invention. FIG. 10A is a connector of the upper member 10 when the upper member 10 is mounted on the upper side. 22 is a front view from the 22 direction, (d) is a front view from the direction of the connector 22 of the upper member 10 when the upper member 10 is mounted on the lower side, and (c) is a case of being mounted with the connector 22 on the upper side. It is a top view from the circuit board 20 direction of the upper member 10, and (d) is a top view from the circuit board 20 direction of the upper member 10 when the connector 22 is mounted on the lower side.

  Note that the ECU 100 in the modification 4 has many parts in common with those in the first embodiment and the modifications 1 to 3 described above, and therefore, detailed description of the common parts will be omitted below, and different parts will be emphasized. I will explain it. The modification 4 differs from the first embodiment to modification 3 described above in the shape of the air intrusion prevention wall 11.

  When the air intrusion prevention wall 11 is provided on the upper member 10 or the lower member 12 as described above, the temperature of the air entering from the outside of the case is lowered at the air ingress prevention wall 11. Therefore, condensation occurs on the air intrusion prevention wall 11, and water droplets generated by the condensation may drop onto the circuit board 20 or the like.

  Therefore, in the fourth modification, the shape of the air intrusion prevention wall 11 is inclined as shown in FIG.

  For example, as shown in FIG. 10A, when the ECU 100 is mounted in the horizontal direction with the upper member 10 facing upward, the shape of the air intrusion prevention wall 11 is at least a surface substantially perpendicular to the circuit board 20. The inclined shape is inclined in the direction of gravity as it goes to one side. That is, the air intrusion prevention wall 11 has an inverted mountain shape, and has an inclined shape that inclines in the direction of gravity from the center toward the end.

  As shown in FIG. 10B, when the ECU 100 is mounted in the horizontal direction with the upper member 10 on the lower side, the shape of the air intrusion prevention wall 11 is substantially perpendicular to the circuit board 20. It is set as the inclination shape which inclines in a gravitational direction toward at least one side. That is, the air intrusion prevention wall 11 forms a mountain shape, and has an inclined shape that inclines in the direction of gravity from the center toward the end.

  Further, as shown in FIG. 10C, when the ECU 100 is mounted in the vertical direction with the connector 22 facing upward, the shape of the air intrusion prevention wall 11 is at least one of surfaces substantially perpendicular to the circuit board 20. Inclined shape that inclines in the direction of gravity as it goes to. That is, the air intrusion prevention wall 11 has an inclined shape that is bent so as to incline in the direction of gravity from the center toward the end.

  Further, as shown in FIG. 10D, when the ECU 100 is mounted in the vertical direction with the connector 22 facing downward, the shape of the air intrusion prevention wall 11 is at least on a surface substantially perpendicular to the circuit board 20. The inclined shape is inclined in the direction of gravity as it goes to one side. That is, the air intrusion prevention wall 11 has an inclined shape that is bent so as to incline in the direction of gravity from the center toward the end.

  In the present embodiment, the shape of the air intrusion prevention wall 11 provided on a surface substantially parallel to the circuit board 20 of the upper member 10 has been described, but the present invention is not limited to this. The shape of the air intrusion prevention wall 11 in Modification 4 may be applied to the air ingress prevention wall 11 provided on a surface substantially perpendicular to the circuit board 20 of the upper member 10 and a surface substantially parallel to the circuit board 20 of the lower member 12. .

  In the first embodiment and the first to fourth modifications described above, the example of the case including the upper member 10 and the lower member 12 has been described. However, the present invention is not limited thereto. is not. An air intrusion prevention wall 11 protruding in the direction of the circuit board 20 is provided at least at a part between the position corresponding to the opening side end of the mounting area on the circuit board 20 where the circuit element 21 is mounted. Then, the object of the present invention can be achieved. For example, the case which consists of one member may be sufficient.

  As described above, in a state where the ECU 100 is attached to the attachment target, the air intrusion prevention wall 11 is inclined in the direction of gravity toward the at least one of the surfaces substantially perpendicular to the circuit board 20 or the substantially parallel surfaces. By adopting the shape, it is possible to prevent water droplets adhering to the air intrusion prevention wall 11 due to condensation from dropping on the circuit board 20 or the like.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. FIG. 11 is a diagram showing a schematic configuration of the ECU 100 in the second embodiment of the present invention, (a) is a cross-sectional view of the ECU 100, (b) is a front view from the direction of the connector 22 of the ECU 100, FIG. 3C is a perspective view of the upper member 10.

  Since the ECU 100 in the second embodiment is often in common with that in the first embodiment described above, a detailed description of common parts will be omitted, and different parts will be described mainly. The second embodiment is different from the first embodiment described above in that a radiation fin 13 is provided instead of the air ingress prevention wall 11.

  The upper member 10 in 2nd Embodiment is equipped with the radiation fin 13 instead of the air intrusion prevention wall 11, as shown in FIG.

  As shown in FIGS. 11 (b) and 11 (c), the heat radiating fin 13 is composed of a plurality of protrusions provided from one end to the other end on a surface substantially parallel to the circuit board 20 of the upper member 10. . The radiating fin 13 is at least a part between the position corresponding to the opening side end of the mounting region where the circuit element 21 is mounted on the circuit board 20 of the upper member 10 and the opening of the upper member 10. And is provided so as to protrude in the direction of the circuit board 20. In addition, although the one where the clearance gap between the radiation fin 13 and the electronic device 200 is smaller is preferable, when the assembly | attachment tolerance of the upper member 10, the lower member 12, and the connector 22 is considered, about 0.5-3 mm is preferable.

  When the electronic device 200 includes a terminal 23 that electrically connects the circuit board 20 and the connector 22, the radiating fin 13 has a length that does not contact the terminal 23, as shown in FIG. Shape. Moreover, although the radiation fin 13 was demonstrated in this Embodiment using the example which provides a some protrusion from one edge part in the surface substantially parallel to the circuit board 20 of the upper member 10 to the other edge part. The present invention is not limited to this, and may be provided at a position corresponding to a gap generated between the upper member 10 and the connector 22.

  Thus, by providing the case (upper member 10) with the radiating fins 13, the temperature of the air entering the case is reduced by the radiating fins 13, and the humidity of the air entering the case is reduced. be able to. Therefore, it is possible to prevent the occurrence of condensation on the circuit board 20 and the circuit element 21 in the case.

  Therefore, by providing the radiating fins 13 on a surface substantially parallel to the circuit board 20 of the case (upper member 10), dew condensation on the circuit board 20 and the circuit element 21 in the case can be prevented without using a moisture-proofing agent or packing. Therefore, it is possible to prevent the occurrence of condensation on the electronic device 200 in the case while suppressing cost.

(Modification 1)
In the above-described embodiment, the heat radiating fins 13 are described using an example in which the radiating fins 13 are provided on a surface substantially parallel to the circuit board 20 in the upper member 10, but the present invention is not limited to this.

  The radiation fin 13 of the modification 1 in 2nd Embodiment is demonstrated. FIGS. 12A and 12B are diagrams showing a schematic configuration of the ECU 100 according to the first modification of the second embodiment of the present invention. FIG. 12A is a cross-sectional view of the ECU 100, and FIG. FIG. 3C is a front view, and FIG. 3C is a perspective view of the upper member 10. The ECU 100 in the first modification is often in common with that according to the above-described second embodiment, and therefore, detailed description of common parts will be omitted and different parts will be described mainly. The modification 1 is different from the above-described second embodiment in the installation position of the radiation fins 13.

  When the upper member 10 and the lower member 12 are assembled, a gap may be generated due to an assembly tolerance between the side surface of the upper member 10 and the connector 22. Even when a gap is generated between the side surface of the upper member 10 and the connector 22, air containing moisture may enter the case from the gap. Further, when air containing moisture enters the case, condensation may occur in the electronic device 200. If dew condensation occurs on the electronic device 200, particularly the circuit board 20 or the circuit element 21, it may cause a malfunction such as a short circuit or corrosion.

  Therefore, as shown in FIGS. 12A to 12C, the heat radiating fins 13 in Modification 1 are provided from one end portion to the other end portion of the surface of the upper member 10 that is substantially perpendicular to the circuit board 20. It consists of a plurality of protrusions. The radiating fin 13 is at least a part between the position corresponding to the opening side end of the mounting region where the circuit element 21 is mounted on the circuit board 20 of the upper member 10 and the opening of the upper member 10. And is provided so as to protrude in the direction of the circuit board 20. In addition, although the one where the clearance gap between the radiation fin 13 and the electronic device 200 is smaller is preferable, when the assembly | attachment tolerance of the upper member 10, the lower member 12, and the connector 22 is considered, about 0.5-3 mm is preferable.

  When the electronic device 200 includes a terminal 23 that electrically connects the circuit board 20 and the connector 22, the heat dissipating fins 13 have a length that does not contact the terminal 23 as shown in FIG. . Further, in the present embodiment, the radiating fin 13 has been described using an example in which the radiating fin 13 is provided from one end portion to the other end portion on a surface substantially perpendicular to the circuit board 20 of the upper member 10. It is not limited to this, and it may be provided at a position corresponding to a gap generated between the upper member 10 and the connector 22.

  Thus, by providing the radiation fin 13 on the side surface of the upper member 10, it is possible to prevent the occurrence of condensation on the circuit board 20 and the circuit element 21 in the case without using a desiccant or packing. Generation | occurrence | production of the dew condensation to the electronic device 200 in a case can be prevented, suppressing cost.

(Modification 2)
In the above-described embodiment, the heat radiating fins 13 are described as being provided on the surface of the upper member 10 that is substantially perpendicular to the circuit board 20, but the present invention is not limited to this.

  The radiation fin 13 of the modification 2 in 2nd Embodiment is demonstrated. FIGS. 13A and 13B are diagrams showing a schematic configuration of the ECU 100 according to the second modification of the second embodiment of the present invention. FIG. 13A is a cross-sectional view of the ECU 100, and FIG. 13B is a view from the direction of the connector 22 of the ECU 100. FIG. 3C is a front view, and FIG. 3C is a perspective view of the lower member 12. The ECU 100 in the second modification is often in common with that according to the above-described second embodiment, and therefore, detailed description of common parts will be omitted, and different parts will be described mainly. In the second modification, the difference from the above-described second embodiment and the first modification is the installation position of the radiation fins 13.

  When the upper member 10 and the lower member 12 are assembled, there may be a gap between the lower member 12 and the connector 22 due to assembly tolerances. Even when a gap is generated between the lower member 12 and the connector 22, there is a possibility that air containing moisture may enter the case from the gap. Further, when air containing moisture enters the case, condensation may occur in the electronic device 200. If dew condensation occurs on the electronic device 200, particularly the circuit board 20 or the circuit element 21, it may cause a malfunction such as a short circuit or corrosion.

  Therefore, as shown in FIGS. 13A to 13C, the heat dissipating fins 13 in Modification 2 are provided from one end portion to the other end portion of the surface of the lower member 12 substantially parallel to the circuit board 20. It consists of a plurality of protrusions. Further, the radiation fin 13 is at least a part between the position corresponding to the opening side end of the mounting region where the circuit element 21 is mounted on the circuit board 20 of the lower member 12 and the opening of the lower member 12. And is provided so as to protrude in the direction of the circuit board 20. In addition, although the one where the clearance gap between the radiation fin 13 and the electronic device 200 is smaller is preferable, when the assembly | attachment tolerance of the upper member 10, the lower member 12, and the connector 22 is considered, about 0.5-3 mm is preferable.

  When the electronic device 200 includes a terminal 23 that electrically connects the circuit board 20 and the connector 22, the heat radiation fin 13 has a length that does not contact the terminal 23 as shown in FIG. 13B. . Further, in the present embodiment, the radiating fin 13 has been described using an example in which the lower member 12 is provided from one end portion to the other end portion in a plane substantially parallel to the circuit board 20. It is not limited to this, and it may be provided at a position corresponding to the gap formed between the lower member 12 and the connector 22.

  Thus, by providing the heat dissipating fins 13 on the lower member 12, it is possible to prevent the occurrence of condensation on the circuit board 20 and the circuit element 21 in the case without using a moisture-proofing agent or packing, so that the cost can be reduced. Generation | occurrence | production of the dew condensation to the electronic device 200 in a case can be prevented, suppressing.

  In the present embodiment, the lower member 12 having a substantially rectangular plate shape with a shallow bottom has been described as an example. However, the present invention is not limited to this, and the electronic device is similar to the upper member 10. It is good also as the substantially box shape open | released in order to accommodate 200. FIG. In this case, the radiating fins 13 are not limited to those provided on a surface substantially parallel to the circuit board 20 of the lower member 12, but the lower member 12 and the connector such as a surface substantially perpendicular to the circuit board 20 of the lower member 12. What is necessary is just to provide in the position corresponding to the clearance gap which produces between.

  In addition, in the above-mentioned 2nd Embodiment and the modification 1 or the modification 2, although demonstrated using the example of the case which consists of the upper member 10 and the lower member 12, this invention is limited to this. is not. The object of the present invention can be achieved as long as the heat dissipating fins 13 are provided at least at a part between the opening corresponding to the opening side end of the mounting region where the circuit element 21 is mounted on the circuit board 20. Is. For example, the case which consists of one member may be sufficient.

  As described above, the heat radiating fins 13 may also have an inclined shape that inclines in the direction of gravity when the ECU 100 is mounted in the same manner as the air intrusion prevention wall 12. Thus, even if the radiating fins 13 have an inclined shape, it is possible to prevent water droplets attached to the radiating fins 13 due to condensation from dropping on the circuit board 20 or the like.

(Third embodiment)
Next, a second embodiment of the present invention will be described. 14A and 14B are views for explaining the water discharge portion 14 of the ECU 100 according to the third embodiment of the present invention. FIG. 14A is a perspective view of the upper member 10 and FIG. 14B is an enlarged view of the water discharge portion 14. It is a top view, (c) is an expanded sectional view of the water discharge | release part 14. FIG.

  Since the ECU 100 in the third embodiment is often in common with that in the first and second embodiments described above, detailed description of the common parts will be omitted, and different parts will be described mainly. . The second embodiment is different from the first and second embodiments described above in that a water discharge portion 14 is provided.

  The upper member 10 in 2nd Embodiment is provided with the water discharge part 14 instead of the air intrusion prevention wall 11, as shown in FIG.

  The water discharge part 14 is provided in the upper member 10, as shown to Fig.14 (a). Thus, by providing the upper member 10 with the water discharge portion 14, even when condensation occurs in the ECU 100, it is possible to discharge water droplets to the outside, thereby suppressing the water droplets from adhering to the electronic device 200. Can do. It is preferable that the water discharge portion 14 is provided at a position that becomes the bottom in the mounted state of the ECU 100 because water droplets are more easily discharged to the outside.

  Further, as shown in FIGS. 14B and 14C, when the water discharge unit 14 includes the hydrophobic fiber 15 that is an ingress prevention unit that prevents the ingress of liquid from the outside, the water droplets in the ECU 100 are externally removed. In addition, it is preferable that the liquid enters the ECU 100 and the liquid can be prevented from entering from the outside of the ECU 100. The hydrophobic fiber 15 is made of any one of polypropylene, polyacetal, and polyethylene. Further, the hydrophobic fiber 15 is formed in a direction from the inner peripheral portion of the water discharge portion 14 toward the central axis of the water discharge portion 14, and as it goes from the inner peripheral portion of the water discharge portion 14 toward the central axis of the water discharge portion 14. It is formed to face outward.

  In the present embodiment, the water discharge portion 14 has been described using an example provided on the upper member 10, but the present invention is not limited to this, and may be provided on the lower member 12. You may make it provide in both the member 10 and the lower member 12. FIG.

(Modification 1)
As a first modification of the third embodiment, in the above-described embodiment, the water discharge portion 14 may be provided as a separate member from the case (upper member 10 and lower member 12). FIGS. 15A and 15B are diagrams illustrating the water discharge unit 14 of the ECU 100 according to the first modification of the third embodiment of the present invention. FIG. 15A is a perspective view of the water discharge unit 14 and FIG. FIG. 4 is an enlarged cross-sectional view of the discharge unit 14.

  The water discharge | release part 14 comprises a cylinder shape as shown to Fig.15 (a). Hydrophobic fibers 15 are formed on the inner periphery of the cylindrical water discharge portion 14. The water discharge portion 14 is mounted on the upper member 10 via the O-ring 17.

  It should be noted that the first to third embodiments described above and the modifications in each embodiment may be implemented independently or in combination.

  In addition, in the above-mentioned 3rd Embodiment and the modification 1, although demonstrated using the example of the case which consists of the upper member 10 and the lower member 12, this invention is not limited to this. The object of the present invention can be achieved as long as the water discharge portion 14 that discharges water droplets adhering to the inner peripheral portion of the case to the outside is provided. For example, the case which consists of one member may be sufficient.

It is sectional drawing before the assembly | attachment which shows schematic structure of ECU100 in the 1st Embodiment of this invention. It is sectional drawing after the assembly | attachment which shows schematic structure of ECU100 in the 1st Embodiment of this invention. It is a perspective view which shows schematic structure of the upper member 10 in the 1st Embodiment of this invention. It is sectional drawing explaining the approach of moisture of ECU100 in the 1st Embodiment of this invention. It is sectional drawing which shows schematic structure of ECU100 of the modification 1 in the 1st Embodiment of this invention. It is a perspective view which shows schematic structure of the lower member 12 of the modification 1 in the 1st Embodiment of this invention. It is sectional drawing which shows schematic structure of ECU100 of the modification 2 in the 1st Embodiment of this invention. It is a perspective view which shows schematic structure of the upper member 10 of the modification 2 in the 1st Embodiment of this invention. It is sectional drawing explaining the air intrusion prevention wall 11 of the modification 3 in the 1st Embodiment of this invention, (a) is a case where it forms in the upper surface of the upper member 10, (b) is an upper member 10 is formed on the side surface of the lower member 12, and FIG. It is a figure explaining the air entry prevention wall 11 of the modification 4 in the 1st Embodiment of this invention, (a) is from the connector 22 direction of the upper member 10 in the case of mounting with the upper member 10 facing up. FIG. 4D is a front view of the upper member 10 when the upper member 10 is mounted with the upper member 10 facing down, and FIG. 5C is the front member 10 when the upper member 10 is mounted with the connector 22 facing upward. FIG. 4D is a plan view from the direction of the circuit board 20 of the upper member 10 when the connector 22 is mounted with the connector 22 facing down. It is a figure which shows schematic structure of ECU100 in the 2nd Embodiment of this invention, (a) is sectional drawing of ECU100, (b) is a front view from the connector 22 direction of ECU100, (c) is 3 is a perspective view of an upper member 10. FIG. It is a figure which shows schematic structure of ECU100 of the modification 1 in the 2nd Embodiment of this invention, (a) is sectional drawing of ECU100, (b) is a front view from the connector 22 direction of ECU100, FIG. 3C is a perspective view of the upper member 10. It is a figure which shows schematic structure of ECU100 of the modification 2 in the 2nd Embodiment of this invention, (a) is sectional drawing of ECU100, (b) is a front view from the connector 22 direction of ECU100, (C) is a perspective view of the lower member 12. It is a figure explaining the water discharge part 14 of ECU100 in the 3rd Embodiment of this invention, (a) is a perspective view of the upper member 10, (b) is an enlarged plan view of the water discharge part 14. (C) is an expanded sectional view of the water discharge part 14. It is a figure explaining the water discharge part 14 of ECU100 of the modification 1 in the 3rd Embodiment of this invention, (a) is a perspective view of the water discharge part 14, (b) is the water discharge part 14 It is an expanded sectional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Upper member, 11 Air ingress prevention wall, 12 Lower member, 13 Radiation fin, 14 Water discharge part, 15 Hydrophobic fiber, 20 Circuit board, 21 Circuit element, 22 Connector, 23 Terminal, 100 ECU, 200 Electronic device

Claims (14)

A housing for an electronic device that houses an electronic device comprising a circuit board on which circuit elements are mounted, and an external connection part that performs electrical connection between the circuit board and the outside,
An opening that exposes at least a portion of the external connection portion to the outside;
It is at least a part between a position corresponding to the opening side end of the mounting region where the circuit element is mounted on the circuit board and the opening , and is substantially perpendicular to the mounting surface of the circuit element on the circuit board Lowering the humidity of the air by lowering the temperature of the incoming air, which is provided projecting in the direction of the circuit board on at least one of the inner surfaces of the housing or at least one of the inner surfaces of the substantially parallel housing , With an air ingress prevention wall that prevents ingress of air in high humidity and high temperature conditions ,
The air entry wall has an inclined shape that inclines in the gravitational direction toward at least one of surfaces that are substantially perpendicular to a mounting surface of the circuit element on the circuit board in a state where the electronic device casing is attached to an attachment target. electronic device housing, characterized that you and. 2. The electronic device casing according to claim 1 , wherein the air entry prevention wall is provided from one end to the other end of the substantially parallel surface. The air intrusion preventing wall, an electronic device housing according to claim 1 or claim 2, characterized in that it is provided with a plurality on the substantially parallel surfaces. 2. The electronic device casing according to claim 1 , wherein the air intrusion prevention wall is provided from one end to the other end of the substantially vertical surface. The air intrusion preventing wall, an electronic device housing according to claim 1 or claim 4, characterized in that it is more provided in the substantially vertical plane. The electronic device casing according to any one of claims 1 to 5 , further comprising a water discharge portion that discharges water droplets adhering to the inner peripheral portion to the outside. The electronic device casing according to claim 6 , wherein the water discharge portion is provided at a position to be a bottom in a state where the electronic device casing is attached to an attachment target. The water discharge unit, the electronic device enclosure of claim 6 or claim 7, characterized in that it comprises an entry preventing portion for preventing the ingress of liquid from the outside. The intrusion prevention unit includes a hydrophobic fiber formed in a direction from the inner peripheral portion of the water discharge portion toward the central axis of the water discharge portion, and the hydrophobic fiber extends from the inner peripheral portion of the water discharge portion. The casing for an electronic device according to claim 8 , wherein the casing for the electronic device is directed outward as it goes toward the central axis of the water discharge portion. The electronic device casing according to claim 9 , wherein the hydrophobic fiber is made of any one of polypropylene, polyacetal, and polyethylene. The water discharge unit, the electronic device housing to according to any one of claims 6 to 10, characterized in that said a housing member separate electronics. The casing for an electronic device according to any one of claims 1 to 11 , wherein the casing is made of a resin material. Electronic置用housing according to any one of claims 1 to 11, characterized in that made of aluminum. The casing for an electronic device according to any one of claims 1 to 11 , wherein the casing is made of iron.

Images