JP2010093129A - Electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic device which houses an electronic component to be installed outdoors, the electronic device having a structure meeting a waterproof standard and facilitating replacement of the electronic component housed inside. <P>SOLUTION: The problem is achieved by constituting the electronic device as follows. The electronic device includes: a housing constructed of a case having an opening and an air vent, and a cover; and an internal unit configured of a heatsink where the electronic component is mounted, the heatsink dissipating heat generated by the electronic component, and heat radiating fins which are inserted into the opening of the case. The heat sink includes a draining portion extending in a direction perpendicular to the extending direction of the heat radiating fins below the heat radiating fins, and projections for engagement at two positions above a groove for waterproofing and the heat radiating fins at a periphery except above the heat radiating fins, and the case has holes for engagement at two places above a waterproofing rib and the opening at a periphery except above the opening. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic device, and more particularly to an electronic device installed outdoors.

  North American outdoor enclosures must meet North American proprietary standards. In particular, regarding waterproofing, it is necessary to pass the following three tests described in Non-Patent Document 1. Of the three tests, the Wind Drive Rain test is the most severe test.

1. Wind Drive Rain test In an environment where the rainfall is 150 mm / hr and the wind speed is 31 m / sec, water is sprayed on each of the front, right side, and left side for 30 minutes, and the amount of water entering the housing is 1 cm ^ 3 (1 gram of water) per 0.028m ^ 3 (1ft ^ 3).

2. Rain Intrusion Test Immediately after a heavy rain, water droplets that have accumulated on the surface or door grooves should not enter the interior of the housing. Water shall be sprayed for 15 minutes each on the front and both sides, and the amount of water entering the housing shall not exceed 1 cm ^ 3 (1 gram of water) per 0.028 m ^ 3 (1 ft ^ 3).

3. Lawn Sprinklers test After discharging water from below 45 ° simulating a sprinkler (front and both sides 15 minutes each: 45 minutes in total), the amount of water intrusion into the housing is 1 cm ^ 3 (1 gram of water) per 0.028 m ^ Do not exceed 3 (1ft ^ 3).

  In addition to the waterproof standards described above, outdoor installation housings for North America are required to be able to easily replace electronic components housed inside. That is, it is necessary to have a structure in which the internal unit including the electronic components inside the housing can be replaced, instead of replacing the entire device during maintenance and replacement of the device. This is also a specification that allows the housing to be installed first and the internal unit to be installed at a later date.

  The housing material is preferably resin from the viewpoint of cost and mass. However, it is difficult to ensure sufficient heat dissipation performance with a resin sealed casing. Therefore, it is necessary to provide heat radiating performance by providing a vent hole in the resin casing and exposing only a part of the heat radiating fin of the heat sink thermally connected to the electronic component to the outside of the resin casing. Here, water may be applied to the heat radiating fins, but water should not enter into portions other than the heat radiating fins.

  Furthermore, the electronic component and the heat sink are generally connected by a heat conductive sheet. For this reason, it is difficult to remove only the board on which the electronic component is mounted during maintenance and replacement, and the electronic component must be removed and replaced together with the heat sink. This exchange unit is called an internal unit.

  The inventors of the present application have invented an electronic device that can efficiently conduct heat from the inside of the housing to the outside of the housing and can exchange the internal unit in the previous application. The housing structure of this electronic device includes a heat sink for dissipating internal heat, and the heat dissipation surface of the heat sink is exposed on the bottom surface of the housing, so that the efficiency of heat dissipation from the inside of the housing to the outside of the housing is achieved. This is an improved structure. The lower part of the heat radiating fin is provided with a eaves structure for preventing water from entering the housing. In addition to this eaves structure, the rib formed on the entire circumference of the opening for the heat sink of the case and the groove formed on the entire circumference of the heat sink are fitted to each other so that it is waterproof without using a packing between the case and the heat sink. Satisfied performance. However, this structure requires 8 screws to attach the internal unit. All these screws must be removed and replaced during the replacement operation. Further, since the internal unit cannot be fixed to the case in a state where the screw is not fixed, the internal unit may drop off during the replacement work, and the replacement workability is not good.

“Generic Requirements for Electronic Equipment Cabinets”, Telcordia Technologies, March 2000, GR-487-CORE issue 2, Section 3.28

  A countermeasure against the dropout of the internal unit during the replacement work will be described with reference to FIG. Here, FIG. 1A is a cross-sectional view corresponding to AA of FIG. For simplicity, the unit cover 510 is omitted, and the hole 104 of the case 10 shows a cross section corresponding to BB. FIG.1 (b) is the elements on larger scale of the C section of Fig.1 (a). As apparent from FIG. 1, the internal unit dropout plan in FIG. 1 is obtained by fitting the hole 104 of the case 10 and the protrusion 532 of the heat sink 530 and rotating about the y axis. The unit 40 is prevented from falling off. However, the first groove 533 and the second groove 534 of the heat sink 530 are present in the portion C in the y-axis method of the heat radiation fin 540. In addition, the first rib 101 and the second rib 102 of the case 10 are present above the opening 130. In this case, since the protrusion 532 cannot be inserted into the hole 104, the case 10 and the heat sink 530 cannot be fitted.

The present invention provides an electronic device that can be installed outdoors, which satisfies North American waterproof standards and can replace internal units including electronic components.
The present invention further provides an electronic device that can easily replace the internal unit in an electronic device that is installed outdoors that can meet the North American waterproof standard and replace the internal unit including electronic components.

  The above-described problem is that a heat sink that mounts an electronic component on a housing including a case having an opening and a cover and absorbs heat generated by the electronic component, and a plurality of heat dissipations that are formed on the heat sink and radiate heat from the heat sink. The case is formed by inserting the heat radiation fin of the internal unit formed in the heat sink and having a draining portion extending in a direction perpendicular to the direction in which the heat radiation fin extends in the lower portion of the heat radiation fin. The heat sink can be solved by an electronic device having a U-shaped rib around the top of the heat sink and a groove formed so as to sandwich the rib around the top of the heat radiating fin. In addition, when connecting the internal unit connected to the heat sink to the case (case) in a plane including the vertical direction, the inner side of the heat sink that prevents the front unit from collapsing in the forward direction with the lower side of the internal unit as the rotation axis is used. There are protrusions on the top to prevent falling off and holes that fit into the protrusions of the heat sink of the case. Ribs are formed on the three sides excluding the upper side of the opening for the heat sink of the case, and are formed on the three sides excluding the upper side of the heat sink. This can be solved by an electronic device that fits the groove.

  According to the present invention, it is possible to provide an electronic device installed outdoors that can meet the North American waterproof standard and can replace an internal unit including electronic components. Further, according to the present invention, an electronic device that can be easily replaced can be provided in an electronic device that is installed outdoors that can meet the waterproofing standard of North America and replace an internal unit including electronic components.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings using examples. The same reference numerals are assigned to substantially the same parts, and the description will not be repeated. Here, FIG. 2 is a perspective view showing a state in which the housing is attached to the outdoor wall surface. FIG. 3 is a perspective view of the back side of the housing. FIG. 4 is a perspective view showing a state where the cover of the casing of the electronic device is opened. FIG. 5 is a front view of the housing case. FIG. 6 is a front view of the heat sink on the side of the radiation fin. FIG. 7 is an assembled cross-sectional view of the electronic device. FIG. 8 is a cross-sectional view of the electronic device. FIG. 9 is a cross-sectional view around the eaves portion. FIG. 10 is a sectional view around the gap between the upper heat sink and the case. FIG. 11 is a cross-sectional view in another direction around the gap between the upper heat sink and the case.

  In FIG. 2, the outdoor housing 1 is composed of a case 10 and a cover 20, and is fixed to a wall surface 70. The case 10 and the cover 20 are all made of resin. As shown in FIG. 3, the case 10 includes a lower vent hole 110 and an upper vent hole 120 for cooling channels. The outdoor housing 1 can mount the internal unit 40 to be mounted later while being fixed to the wall surface 70. In FIG. 3, the lower vent hole 110 is not shown because of the perspective direction, but is clearly shown in FIG. 8 shown later. Further, in FIG. 3 and FIG. 5 to be described later, the illustration of the attachment hole to the wall surface 70 is omitted.

  In FIG. 4, the electronic apparatus 1000 shows a state where the cover 20 is opened. The electronic apparatus 1000 is in a state where the internal unit 40 is connected to the outdoor housing 1. In FIG. 4, the cover 20 and the case 10 are connected by the hinge 30, but the cover 20 may be removable and may be fixed to the case 10 with screws. Moreover, the cover 20 and the case 10 are resin-sealed structures, and a watertight structure can be easily realized.

  The case 10 will be described with reference to FIG. In FIG. 5, the maximum outer shape of the case 10 is approximately 303 × 296 mm, and has a frame-side hinge 31 on the left side and an opening 130 of 122 × 212 mm in the center. A first rib 101 and a second rib 102 are provided around the periphery of the opening 130 except for the upper side. In addition, two screw holes 103 for fixing the internal unit 40 are provided in the lower portion of the opening 130 of the case 10. Furthermore, the upper part of the opening part 130 of the case 10 has two holes 104 in the xy plane downward for fitting the internal unit 40. The case 10 has two ribs 105 for receiving the internal unit 40 in the z-axis direction.

  The heat sink 530 will be described with reference to FIG. In FIG. 6, the maximum outer shape of the heat sink 530 is 179.5 × 265 mm, and has heat radiation fins 540. Below the radiating fins 540, there are eaves 531, and below the eaves 531, there are two holes 535 used when fixing the internal unit 40. The eaves 531 separates the water droplets traced between the radiation fins 540 from the vertical plane portion of the heat sink 530 main body. Further, a first groove 533 and a second groove 534 are provided around the periphery of the radiating fin 540 except for the upper side. Note that the first groove 533 and the second groove 534 penetrate the heat sink 530 in the z direction. The heat sink 530 is provided with protrusions 532 that are used when fitting the internal unit 40 at both upper ends thereof.

  With reference to FIG. 7, each component of the electronic apparatus 1000 will be described. 7 is a cross-sectional view corresponding to AA in FIG. In FIG. 7, the electronic apparatus 1000 is configured such that the internal unit 40 is attached to the case 10 and the cover 20 is further covered.

  The internal unit 40 includes a heat sink 530, a heat conductive sheet 550, an electronic component 560, a substrate 520, a unit cover 510, and a substrate fixing screw 570. The electronic component 560 is mounted on the substrate 520 and transfers heat to the heat sink 530 through the heat conductive sheet 550. The heat sink 530 radiates heat from the radiation fins 540 to the air outside the housing. When the internal unit 40 is fixed to the case 10, two internal unit fixing screws 580 are used. The case 10 shows the hole 104 described with reference to FIG. 5 and the side surface of the rib 105.

  With reference to FIG. 8, a cross-sectional configuration after assembly as electronic device 1000 will be described. FIG. 8 is also a cross-sectional view corresponding to AA in FIG. Further, for simplicity, the unit cover 510 is omitted, and the hole 104 of the case 10 shows a cross section corresponding to BB in FIG. In FIG. 8, the air that has flowed in from the lower ventilation hole 110 of the case 10 flows upward while taking the heat of the radiating fins 540 and flows out from the upper ventilation hole 120. As shown in FIG. 5, the case 10 includes the opening 130, and the heat radiating fins 540 are inserted into the case 130, and the case 10 is cooled by being brought into contact with the outside air flowing from the lower ventilation holes 110. The size of the opening 130 is determined by the size of the radiation fin 540 to be exposed. The size of the radiating fin 540 is determined from the results of thermal simulation and temperature test.

  When attaching the internal unit 40 to the case 10, first, the protrusion 532 at the top of the heat sink 530 is inserted into the hole 104 of the case 10, and when the heat sink fin 540 is inserted to the back, the radiating fin 540 is inserted into the opening 130 of the case 10. As a result, the rib 105 of the case 10 receives the lower end surface of the heat sink 530 so that the internal unit 40 does not fall down. Further, since the protrusion 532 is inserted into the hole 104 of the case 10, the internal unit 40 does not fall down in the front direction. For this reason, the mounting operation of the internal unit 40 can be performed without worrying about the falling off of the internal unit 40 even in a state where the screws are not fixed during the replacement operation.

  With reference to FIG. 9, the mechanism which can endure a waterproof test is demonstrated. FIG. 9A is a cross-sectional view corresponding to AA in FIG. Moreover, FIG.9 (b) is the E section enlarged view of Fig.9 (a). In FIG. 9, water entering from the upper vent 120 in the waterproof test flows down the heat sink 530. However, the eaves 531 serve as a draining portion and prevents the eaves 531 from flowing into the gap 60 between the lower heat sink and the case. This prevents most of the water from flowing into the gap between the lower heat sink and the case. Further, when it slightly flows, the first groove 533 and the second groove 534 provided in the heat sink 530, and the first rib 101 and the second rib 102 provided in the case 10 are fitted. Since a slight space is provided in the part, water can be prevented from entering the housing by using surface tension to hold water in this space.

  Next, the flow of water around the upper vent 120 will be described with reference to FIGS. 10 and 11. Here, FIG. 10A is a cross-section corresponding to AA in FIG. 5, the unit cover 510 is omitted for simplicity, and the hole 104 shows a cross-section corresponding to BB in FIG. 5. Moreover, FIG.10 (b) is the F section enlarged view of Fig.10 (a). Further, FIG. 11A is a cross-sectional view corresponding to GG in FIG. FIG.11 (b) is the H section enlarged view of Fig.11 (a).

  In FIG. 10, when the water flowing from the upper vent hole 120 reaches the gap 61 between the upper heat sink and the case, the water is sucked upward by a capillary phenomenon. The water drawn up upwards then spreads over the entire area where the capillaries are formed. Therefore, the gap 61 between the upper heat sink and the case in FIG. 11 spreads in the horizontal direction and reaches the first groove 533. Since a minute space exists in the first groove 533, capillary action does not occur, and water does not spread laterally across the first groove 533. Water stays in the first groove 533 due to surface tension or flows downward along the first groove 533. Even if the first groove 533 is crossed, the water remains in the second groove 534 due to surface tension or flows downward along the second groove 534. This prevents water from entering the housing. As described above, it is preferable that the first groove 533 and the second groove 534 reach the upper end surface of the heat sink 530 in order to prevent the water sucked up by the capillary phenomenon from entering the inside of the housing.

  This is because, if these grooves do not reach the upper end surface of the heat sink 530 and are interrupted at a position 10 mm from the upper end surface, there is a possibility that a portion without the grooves becomes a path of water flow. The first groove 533 and the second groove 534 block this path. Therefore, it is preferable that the first groove 533 and the second groove 534 reach the upper end surface of the heat sink 530.

  The electronic device according to the above-described embodiment passed the IPX5 waterproof test of the international standard IEC / EN60529 (JIS standard C0920). According to the inventors' experience, if the waterproof test of IPX5 is passed, the waterproof test of Wind Drive Rain will pass without any problem.

  According to the embodiment described above, the internal unit can be temporarily fixed to the housing. Also, the number of screws can be reduced from two to two. Therefore, workability at the time of installation / replacement of the internal unit is good.

It is principal part assembly sectional drawing explaining the drop-off countermeasure of the internal unit of an electronic device. It is a perspective view which shows the state which attached the housing | casing to the outdoor wall surface. It is a back surface perspective view of a housing | casing. It is a perspective view of the state where the cover of the electronic device was opened. It is a front view of a housing | casing case. It is a front view by the side of the radiation fin of a heat sink. It is an assembly sectional view of an electronic device. It is sectional drawing of an electronic device. It is sectional drawing of eaves structure periphery. It is an enlarged view of the fitting part of a projection part and a hole part. It is sectional drawing of the clearance gap periphery between an upper heat sink and a case.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Outdoor housing | casing, 10 ... Case, 20 ... Cover, 30 ... Hinge, 31 ... Frame side hinge part, 40 ... Internal unit, 60 ... Clearance between lower heat sink-case, 61 ... Clearance between upper heat sink-case, DESCRIPTION OF SYMBOLS 70 ... Wall surface, 101 ... 1st rib, 102 ... 2nd rib, 103 ... Screw hole, 104 ... Hole part, 105 ... Rib, 110 ... Lower side vent hole, 120 ... Upper side vent hole, 130 ... Opening part, 510 ... Unit cover, 520 ... Substrate, 530 ... Heat sink, 531 ... Eave, 532 ... Projection, 533 ... First groove, 534 ... Second groove, 535 ... Screw hole, 540 ... Radiation fin, 550 ... Thermal conduction Sheet, 560... Electronic component, 570... Board fixing screw, 580... Internal unit fixing screw, 1000.

Claims (4)

In the case consisting of a case with an opening and a cover,
A heat sink that mounts an electronic component and absorbs heat generated by the electronic component, a plurality of radiating fins that are formed on the heat sink and radiates heat from the heat sink, and is formed on the heat sink, and the radiating fin is disposed below the radiating fin. In the electronic device formed by inserting the radiating fin of the internal unit having a draining portion extending in a direction perpendicular to the extending direction of
The case has ribs in a U shape around the top of the opening,
2. The electronic apparatus according to claim 1, wherein the heat sink has a groove formed so as to sandwich the rib around the periphery of the heat radiating fin. An electronic device according to claim 1,
The heat sink has a protrusion for fitting on the upper end surface of the heat sink,
The electronic device according to claim 1, wherein the case includes a hole portion into which the protrusion portion is inserted and a placement portion on which a lower end surface of the heat sink is placed at a position corresponding to the protrusion portion of the heat sink. An electronic device according to claim 1 or claim 2,
Both ends of the groove are formed up to the upper end surface of the heat sink. An electronic device according to any one of claims 1 to 3, comprising:
An electronic apparatus comprising a plurality of the grooves and the ribs.

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