JP3414308B2 - Electronic device storage box - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device housing box provided for housing an electronic device such as an electronic control unit in a vehicle, for example. 2. Description of the Related Art Conventionally, a vehicle is provided with an electronic control unit comprising a semiconductor electronic device such as a microcomputer and a memory for controlling fuel injection and ignition timing for an engine. Semiconductor electronic devices are generally vulnerable to heat,
The electronic control unit is often installed in a high-temperature environment due to the heat of the engine. Therefore, in order to protect the semiconductor electronic device from heat, the electronic control unit is sometimes housed in a special case made of a synthetic resin. The applicant of the present invention has proposed in Japanese Patent Application Laid-Open No. Hei 9-74641 a housing box for an electronic control unit in which the electronic control unit can be installed in an engine room at a high temperature. As shown in FIG. 6, the housing box 50 includes an inner box 51 that houses the electronic control unit E, and an outer box 52 that houses the inner box 51, and a space between the inner box 51 and the outer box 52. Air chamber 53 for buffering heat transfer
Is provided. Each of the inner box 51 and the outer box 52 is formed as a box having an opening on the upper side.
4, the electronic control unit E can be taken out. According to the storage box 50, the transfer of heat from the outside to the electronic control unit E is performed by the double boxes 51 and 52.
And the air chamber 53, it is possible to prevent the electronic control unit E from being exposed to excessively high heat in a high-temperature environment such as an engine room. Such a storage box 50 has a drip-proof structure to prevent water from entering the inside of the inner box due to running on rough roads, high-pressure washing, and the like, so that the electronic control unit E is not damaged by the water. However, there is a possibility that water will enter from the intake port of the wire harness connected to the electronic control unit E to the inside of the inner box 51. In order to prevent water from accumulating in the inner box 51, drainage holes 57 and 58 for discharging water are provided in the bottom plates 55 and 56 of the inner box 51 and the outer box 52, respectively. Is provided. Therefore, the inner box 51 should be used.
Even if water enters inside, water is discharged from the inner box 51 to the air chamber 53, and from the air chamber 53 to the outside of the outer box 52, so that water does not accumulate inside the inner box 51, The electronic control unit E is not immersed in water. Although water may enter the air chamber 53, the water is discharged to the outside of the outer box 52 so as not to accumulate in the air chamber 53 by the drain hole 58 of the outer box 52. The drain holes 57 and 58 are provided so that the amount of water entering the inner box 51 and the air chamber 53 is small, and that the drain holes 57 and 58 pass through the drain holes 57 and 58 from the outside of the storage box 50 to the inside of the inner box 51. In order to prevent water from entering in reverse, the opening area is not formed so large. [0005] However, since each of the drain holes 57 and 58 is merely provided with an opening, if a large amount of water is applied to the bottom surface of the storage box 50 by violent force. There is a possibility that water may enter the inner box 51 through the drain hole 58 of the outer box 52, the air chamber 53, and the drain hole 57 of the inner box 51. In addition, dust in the environment in which the storage box 50 is installed may enter the inner box 51 through the drain holes 57 and 58. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide an electronic device having an inner box for housing an electronic device and an outer box for housing the inner device. In addition to suppressing the temperature change of the electronic device due to the temperature change of the installation environment, it is possible to prevent the electronic device from being immersed in the fluid inside the inner box,
An object of the present invention is to provide an electronic device housing box that can prevent dust and the like from entering the inner box. [0007] In order to solve the above problems, the invention according to claim 1 includes an inner box for housing an electronic device, and an outer box for housing the inner box, An air chamber is provided between the outer box and the inner box for buffering heat transfer between the outside of the outer box and the inside of the inner box. A first discharge portion for discharging the fluid to the outside of the inner box so as not to accumulate in the air chamber is provided so as to open to the air chamber, and the outer box is provided with a fluid so that the fluid does not accumulate in the air chamber. In a housing box for an electronic device provided with a second discharge portion for discharging to the outside of the outer box so as to open to the air chamber, the inside of the inner box is provided in the air chamber in the first space.
A discharge unit, an air chamber, and a second discharge unit that communicate with the outside of the outer box;
An electronic device storage box provided with a discharge flow path having a maze structure that suppresses inflow of fluid or gas into the inner box through the air chamber and the first discharge unit. In addition, the inner box and the outer box
Are each integrally molded with synthetic resin,
The discharge passage is formed by a molding die of the inner box or the outer box.
And is formed integrally with the inner box or the outer box. Further
The first discharge portion is formed on a bottom plate of the inner box.
First drain hole penetrating in the direction in which the movable mold for forming the box is removed
Wherein the discharge flow path is formed between an outer surface of a bottom plate of the inner box and a front surface thereof.
The first drain hole is drawn out between the inner surface of the bottom plate of the outer box and the inner surface of the outer box.
Is formed so as to surround the perimeter in the direction
At the same time, the first opening that opens in a part
An inner rib provided with an outer surface of a bottom plate of the inner box and an outer surface of the outer box.
The inner rib is opposed to the inner surface of the bottom plate in the drawing direction.
While being formed to surround along the circumference to
An opening at a portion on the same circumference that does not overlap with the first opening
And an outer rib provided with a second opening,
2 The discharge portion opens to the air chamber outside the outer rib.
It is the 2nd drainage hole formed so that it might be. (Function) According to the first aspect of the present invention, heat is transferred between the electronic device and the electronic device based on a temperature change in an environment in which the housing box housing the electronic device is installed. Is suppressed by air having a low thermal conductivity inside the outer case and the inner case, and inside the air chamber provided between the outer case and the inner case. Further, fluid such as water that has entered the inside of the inner box from the outside of the housing box is discharged to the air chamber side by the first discharge portion provided in the inner box so as not to collect in the inner box. First
The fluid discharged from the discharge unit passes through a discharge flow path provided in the air chamber and is discharged to the outside of the outer case by the second discharge unit provided in the outer case so that the fluid does not accumulate in the air room. Fluid that has directly entered the air chamber from outside the storage box is discharged to the outside of the outer box by the second discharge unit so as not to accumulate in the air chamber. Further, even if the vehicle runs on a rough road or the fluid is vigorously applied to the bottom surface of the storage box by the high-pressure washing, the discharge flow path having the maze structure is formed from the outside of the outer box to the second discharge portion, the air chamber. And the inflow of fluid or gas into the inner box through the first discharge portion. Also, when molding the inner box or outer box,
Since the outlet channel is formed integrally with the inner box or outer box,
Increased number of parts and assembling man-hours due to provision of roads
There is no. In addition, they entered the inner box from outside the storage box
Fluid flows from the first drain hole provided in the bottom plate of the inner box to the inner side.
It flows out to the discharge channel formed by the rib and the outer rib. Exhaustion
The fluid that has flowed into the outlet channel flows out of the air chamber and then
From the air chamber through the second drain hole provided in the bottom plate,
Spills out. On the other hand, the fluid is strong on the bottom of the storage box
From the second drain hole provided on the bottom plate of the outer box
The fluid that has entered the air chamber is
To the first drain hole by the formed maze discharge channel
Is suppressed. Therefore, the discharge flow path of the maze structure is
It is integrated with the inner box or outer box by the mold for forming the box or outer box.
It is formed and holds the movable mold for molding of the inner box.
A first drain hole through which a pin can be inserted is formed. An embodiment in which the present invention is embodied in a housing box for housing an electronic control unit will be described below with reference to FIGS. FIG. 2 shows a disassembled state of the storage box 10 of the electronic control unit as the storage box for the electronic device. Storage box 10
Is for accommodating the electronic control unit E, and comprises an inner box 11, an outer box 12, and a lid 13 integrally formed of synthetic resin, respectively. The electronic control unit E as an electronic device is for performing, for example, fuel injection control and ignition timing control of the engine, and a circuit board on which the electronic device such as a microcomputer and a memory is mounted is formed of an aluminum alloy. It was housed in the case that was made. FIG. 3 shows a longitudinal section of the storage box 10 in which the electronic control unit E is stored. The inner box 11 is formed in a box having an opening at the upper side so as to accommodate the electronic control unit E. The inner box 11 is provided with an electronic control unit E by a rib (not shown) integrally formed on the inner wall surface.
Is formed so as not to directly contact the inner wall surface. The outer box 12 accommodates the inner box 11,
The upper side is formed in a box having an opening. Outer box 12
Is formed so as to hold the inner box 11 in a state of not directly contacting the inner wall surface by a rib (not shown) integrally formed on the inner wall surface. The lid 13 is provided with an outer box 12 containing the inner box 11.
Is formed so as to cover the opening. The inner box 11, the outer box 12, and the lid 13 are provided with an insertion opening (not shown) for passing a wire harness connected to the electronic control unit E. An air chamber 14 is formed between the inner case 11 and the outer case 12 to suppress heat conduction between the outer case 12 and the inner case 11. Accommodation box 1
Reference numeral 0 denotes a drip-proof structure, and the outer box 12 and the lid 13 form an air exchange opening (not shown) for exchanging the air in the air chamber 14 with the outside air. The opening for air exchange is provided so as to communicate the outside of the housing box 10 with the air chamber 14 so that the air in the heated air chamber 14 can be exchanged with low-temperature outside air. As shown in FIG. 3, the bottom plate 15 of the inner box 11 is drained to the outside of the inner box 11 from the harness insertion opening or the like so that water entering the inner box 11 is not collected. A first drain hole 16 as a first discharge portion is provided. The first drain hole 16 is formed integrally with the inner box 11 by a molding die of the inner box 11, and is formed so as to penetrate therethrough in a movable mold side of the molding die. On the other hand, the bottom plate 17 of the outer box 12 has the first
Water for discharging to the outside of the outer box 12 so that water discharged from the drain hole 16 to the air chamber 14 or water directly entering the air chamber 14 from the harness insertion opening or the air exchange opening does not collect. A second drain hole 18 is provided as a second discharge unit. The second drainage hole 18 is formed integrally with the outer box 12 by a male and female mold for forming the outer box 12, protrudes downward from the lower surface of the bottom plate 17 of the outer box 12, and is formed to open laterally. The air chamber 14 is provided with a discharge passage 19 communicating the inside of the inner box 11 with the outside of the outer box 12 via the first discharge hole 16, the air chamber 14 and the second discharge hole 18. .
The discharge passage 19 is provided from the outside of the outer case 12 to the second drain hole 1.
8, inner box 11 through air chamber 14 and first drain hole 16
A maze structure that suppresses the inflow of fluid such as water, dusty air, etc. into the inside of the vehicle. Discharge channel 19
Are formed integrally with the inner box 11 by a molding die for the inner box 11. FIG. 1 shows the discharge flow path 19 viewed from the inner box 11 side, and FIG. 4 shows a cross section taken along line AA in FIG. The discharge passage 19 includes an annular inner rib 20 surrounding the first drain hole 16 and an annular outer rib 21 surrounding the inner rib 20. The inner rib 20 is provided between the outer surface of the bottom plate 15 of the inner box 11 and the inner surface of the bottom plate 17 of the outer box 12 to form
6 is provided so as to surround the periphery of the movable block with respect to the pulling-out direction of the movable side block, and has a first opening portion 22 that is opened at a part of the periphery. First opening 2
2 is formed to open in a state including the inner surface of the bottom plate 17 of the outer box 17. The outer rib 21 is provided between the outer surface of the bottom plate 15 of the inner box 11 and the inner surface of the bottom plate 17 of the outer box 12,
And a second opening 23 that is formed so as to surround the first opening 22 in a part of the same circumference that does not overlap with the first opening 22. The second opening 23 is formed so as to open in a state including the inner surface of the bottom plate 17 of the outer box 12. The inner rib 20 and the outer rib 21
When the outer case 12 and the outer case 12 are assembled, the lower end thereof is vibration-welded to the upper surface of the bottom plate 17 of the outer case 12. Next, a method of forming the inner box 11 will be described. FIG. 5 shows the inner box 11 in a state where it is molded by the molding dies 30 and 31. The inner box 11 has a fixed mold (cavity block) 30 forming the outer surface thereof.
And the movable mold (core block) 31 forming the inner surface
And molded by. The fixed plate 30 has a bottom plate 15
A pin (cutting pin) 32 for forming the first drain hole 16 is provided at a portion where the discharge flow path 19 is formed. The pin 32 is formed so as to extend through the bottom plate 15 of the inner box 11 to be formed and extend inside the inner box 11. On the other hand, the movable mold 31 has a fitting hole 3 into which the tip of the pin 32 fits.
3 are provided. The pin 32 and the fitting hole 33 are provided for holding the movable mold 31 at a predetermined position with respect to the fixed mold 30. This is because the shape of the inner box 11 is a shape whose thickness is smaller than the depth, so that the position of the movable mold 31 is determined relative to the fixed mold 30 in the thickness direction of the inner box 11. hard. Therefore, by holding the movable mold 31 at a predetermined position by the pins 32 provided on the fixed mold 30, the movable mold 31 is positioned with high accuracy. Next, the operation of the electronic device housing box configured as described above will be described. The conduction between the electronic control unit E and the control unit E based on the temperature change of the environment such as the engine room in which the storage box 10 housing the electronic control unit E is installed is as follows:
The low thermal conductivity inside the outer box 12 and the inner box 11 and the air chamber 14 provided between the outer box 12 and the inner box 11 made of synthetic resin is suppressed by the low air. The water that has entered the inside of the inner box 11 from the outside of the storage box 10 is discharged to the air chamber 14 side by the first discharge hole 16 provided in the inner box 11 so as not to collect inside. The water discharged from the first drain hole 16 passes through a discharge channel 19 provided in the air chamber 14 and passes through the bottom plate 17 of the outer box 12.
Is discharged to the outside of the outer box 12 so as not to be accumulated in the air chamber 14 by the second discharge holes 18 provided in the outer case 12. More specifically, the water discharged from the first drain hole 16 is
Out of the outer rib 21 from the inside through the first opening 22. The water that has flowed into the outer rib 21 moves from the first opening 22 to the second opening 23 according to an annular flow path formed by the inner rib 20 and the outer rib 21, and the second opening 23 is removed. And flows out to the air chamber 14. Air chamber 1
4 flows into the second drain hole 1 provided in the bottom plate 17.
8 and is discharged to the outside of the outer box 12. Further, the air chamber 14 is directly
The water that has entered is discharged to the outside of the outer box 12 by the second drain hole 18 so as not to collect in the air chamber 14. In addition, even if the vehicle runs on a rough road or water is vigorously applied to the bottom surface of the housing box 10 by the high-pressure car washing, the discharge passage 19 having the maze structure is formed from the outside of the outer box 12 to the second discharge hole. 18, the inflow of water into the inner box 11 through the air chamber 14 and the first discharge hole 16 is suppressed. More specifically, the water that has entered the air chamber 14 from the second drain hole 18 also moves to the discharge channel 19 side, but the first drain hole 16 is
Since it is at the end of the discharge flow path 19 of the maze structure formed by
It does not reach the first drain hole 16. Similarly, air containing dust in the environment where the storage box 10 is installed is
Even if the air enters the air chamber 14 through the drain hole 18, the air reaching the first drain hole 16 is suppressed by the discharge passage 19 having the maze structure. Therefore, the temperature change of the electronic control unit E is buffered by the temperature change of the environment in which the electronic control unit E is installed,
Further, the unit E is not immersed in water inside the inner box 11. Further, water, dust, and the like from the outside hardly enter the inside of the inner box 11 through the second drain hole 18 and the first drain hole 16. According to the embodiment described in detail above, the following effects can be obtained. (A) The temperature change of the electronic control unit E is buffered by the temperature change of the environment in which the electronic control unit E is installed, and the unit E is not immersed in water inside the inner box 11. Furthermore, water, dust, and the like enter the inside of the inner box 11 from the outside of the storage box 10 through the second drain hole 18 and the first drain hole 16 by the discharge passage 19 having a maze structure provided in the air chamber 14. hard. Accordingly, the electronic control unit E is provided with an inner case 11 for housing the electronic control unit E and an outer case 12 for housing the inner case 11, and the temperature change of the electronic control unit E due to the temperature change of the environment in which the electronic control unit E is installed. In addition to buffering, the unit E can be prevented from being immersed in water inside the inner box 11, and water, dust, etc. outside the storage box 10 can hardly enter the inner box 11. Can be. (B) The inner case 11 and the outer case 12 are each integrally formed of synthetic resin,
Numeral 9 was formed integrally with the inner box 11 by a molding die for the inner box 11. Therefore, when molding the inner box 11,
Since the discharge channel 19 is formed integrally with the inner box 11, there is no increase in the number of components and the number of assembly steps due to the provision of the discharge channel 19. For this reason, it is possible to prevent the number of parts and the number of assembling steps from increasing. (C) The first discharge hole 16 is formed in the bottom plate 15 of the inner box 11 so as to penetrate the inner box 11 in the direction in which the movable mold for molding 31 of the inner box 11 is removed. The discharge channel 19 is the inner box 1
The first drain hole 16 is formed between the outer surface of the bottom plate 15 and the inner surface of the bottom plate 17 of the outer box 12 so as to surround the first drainage hole 16 along the circumference in the direction in which the movable mold 31 is removed. Between the inner rib 20 having the first opening 22 that opens at a part of the circumference and the outer surface of the bottom plate 15 of the inner box 11 and the inner surface of the bottom plate 17 of the outer box 12, the inner rib 20 is removed in the pull-out direction. While being formed to surround along the circumference,
An outer rib 21 provided with a second opening 23 that is opened at a part on the same circumference that does not overlap with the first opening 22. Further, the second discharge hole is formed so as to open to the air chamber 14 outside the outer rib 21. Therefore, the discharge flow path 19 having the maze structure is the inner box 1
A pin 32 which is formed integrally with the inner box 11 by the first molding die and holds the movable mold 31 of the inner box 11.
Is formed. For this reason,
The molding dimensional accuracy of the inner box 11 can be increased, and the reliability of strength can be secured. Hereinafter, embodiments other than the above-described embodiment embodying the present invention will be listed as other examples. The inner rib 20 and the outer rib 21 constituting the discharge flow path 19 need not be joined to the inner surface of the bottom plate 17 of the outer box 12. The inner ribs 20 forming the discharge passages 19
The outer ribs 21 may be formed integrally with the inner surface of the bottom plate 17 of the outer box 12 by a molding die for the outer box 12. Further, one of the inner rib 20 and the outer rib 21 may be formed integrally with the bottom plate 17 of the outer box 12, and the other may be formed integrally with the bottom plate 15 of the inner box 11. An inner rib 20 constituting the discharge passage 19
The outer rib 21 is integrally formed on the inner surface of the bottom plate 17 of the outer box 12 by the molding die of the outer box 12 and on the outer surface of the bottom plate 15 of the inner box 11 by the molding die of the inner box 11. It may be formed with a part formed integrally. The discharge flow path is not formed integrally with the inner box 11 or the outer box 12 by the molding die for the inner box 11 or the outer box 12, and is independent of the inner box 11 and the outer box 12. The inner box 11 and the outer box 12 may be formed of separate parts and may be attached to predetermined positions by bonding or the like when assembling. This configuration has the effect described in (a) of the above embodiment. The first discharge portion is not limited to the first drain hole 16 formed by the passage of the pin 32 holding the movable mold 31 for molding of the inner box 11. The first discharge unit and the second discharge unit are the inner box 11 and the outer box 1
It is not limited to being formed integrally with the inner box 11 and the outer box 12 by the molding die 2 and may be formed by additionally processing the inner box 11 and the outer box 12. Inner box 1
It may be formed of another member fixed to the outer case 12 and the outer case 12. The discharge flow path having the maze structure is not limited to the one formed by the inner rib formed around the first discharge portion and the outer rib formed around the inner rib. Formed by one partition provided between the first discharge portion and the second discharge portion provided at a position not corresponding to the first portion, and provided with an opening for discharging water from the first discharge portion to the second discharge portion. Flow path may be used. The storage box is not limited to one in which each opening of the inner box and the outer box is closed by a common lid, but the opening of the inner box is closed by the lid for the inner box, and the opening of the outer box is closed. The part may be of a form that is closed by a lid for the outer box. The electronic device includes not only the electronic control unit E but also only a drive circuit. In the following, in addition to the inventions described in the claims, the technical ideas grasped from the above-described embodiments or other examples are described together with their effects. (1) In the first aspect of the present invention,
The inner rib and the outer rib are joined to the inner box or the outer box in which the inner rib and the outer rib are not integrally formed. According to such a configuration, the structural strength of the entire storage box can be improved. (2) In the first aspect of the present invention,
The outer box or the lid is provided with an air exchange opening for exchanging air in the air chamber with air outside the storage box. According to such a configuration, the air in the air chamber heated in the environment where the storage box is installed is exchanged with low-temperature outside air, so that the temperature change of the electronic device can be more effectively suppressed. it can. As described in detail above, according to the first aspect of the present invention, the electronic apparatus is provided with the inner box for housing the electronic device and the outer box for housing the inner box. In addition to buffering changes in the temperature of the electronic device due to changes in the temperature of the environment, it is possible to prevent the electronic device from being immersed in the fluid that has entered the inside of the inner box. It can be difficult to enter. Also, the number of parts
And increase the number of assembly steps.
You. Furthermore, the molding dimensional accuracy of the inner box can be increased.
And reliability of strength can be ensured. [0047]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view of a main part of a storage box showing a discharge channel. FIG. 2 is an exploded schematic perspective view of a storage box. FIG. 3 is a schematic longitudinal sectional view of a storage box. FIG. 4 is a schematic sectional view taken along line AA in FIG. 3; FIG. 5 is a schematic sectional view showing a molding die for the inner box. FIG. 6 is a schematic longitudinal sectional view of a conventional storage box. DESCRIPTION OF SYMBOLS 10: storage box as storage box for electronic device, 11: inner box constituting storage box, 12: outer box, 13: lid, 14: air chamber, 15: bottom plate, Reference numeral 16 denotes a first drain hole as a first discharge portion, 17 denotes a bottom plate, 18 denotes a second drain hole as a second discharge portion, 19 denotes a discharge channel, 20 denotes an inner rib,
DESCRIPTION OF SYMBOLS 1 ... Outer rib, 22 ... 1st opening, 23 ... 2nd opening,
31: movable mold, E: electronic control unit as an electronic device.

Claims (1)

(57) [Claim 1] An inner box accommodating an electronic device, and an outer box accommodating the inner box, wherein the outer box is provided between the outer box and the inner box. An air chamber is provided for buffering the transfer of heat between the outside of the inner box and the inside of the inner box.The inner box is provided for discharging fluid to the outside of the inner box so as not to collect inside the inner box. A first discharge portion is provided so as to open to the air chamber, and the outer box has a second discharge portion for discharging a fluid to the outside of the outer box so that the fluid does not accumulate in the air chamber. In the electronic device housing box provided so as to open to the air chamber, the inside of the inner box communicates with the outside of the outer box via the first discharge portion, the air chamber, and the second discharge portion. to together, the second discharge portion from the outside of the outer box, the flow of fluid or gas into the inside of the inner box through the air chamber and the first discharge portion A discharge flow path having a maze structure for suppressing the occurrence is provided , and the inner box and the outer box are each integrally formed of synthetic resin.
A shall, said discharge flow path, depending on the mold of the inner box or outer box
And the first discharge portion is formed integrally with the inner box or the outer box, and the first discharge portion is formed on the bottom plate of the inner box.
This is a first drain hole that penetrates in the direction in which the movable mold for molding is removed.
Thus, the discharge channel is formed between the outer surface of the bottom plate of the inner box and the bottom of the outer box.
The first drain hole is opposed to the inner surface of the plate in the drawing direction.
While being formed to surround along the circumference to
Inside with a first opening that opens at a part on the same circumference
A rib, an outer surface of a bottom plate of the inner box, and an inner surface of a bottom plate of the outer box
Between the inner rib on the circumference in the pulling direction
Along with the first opening
The second opening that opens at a part on the same circumference that does not overlap with the mouth
An outer rib provided with an opening, wherein the second discharge portion is provided outside the outer rib to the air chamber.
A storage box for an electronic device, which is a second drain hole formed to open .