JP7419995B2 - Automotive electronic equipment - Google Patents

Description

The present invention relates to an on-vehicle electronic device mounted on a vehicle such as an automobile.

For example, vehicles such as automobiles are equipped with various electronic devices called ECUs (Electronic Control Units) as control devices for, for example, multimedia units and car navigation systems. This type of electronic device is configured by accommodating a circuit board on which a heat generating electronic component such as a CPU is mounted in a housing. At this time, in order to cool the electronic components, an intake port and an exhaust port are provided on the left and right side walls of the casing, and a heat sink with fins for dissipating the heat of the electronic components is installed inside the casing. It is configured with a cooling fan and the like for blowing cooling air (for example, see Patent Document 1).

JP2019-96766A

By the way, in the case of the above-mentioned in-vehicle electronic devices, as the operating system is updated every year and the functions are expanded, the hardware functions also need to be updated. However, it is difficult to replace the hardware itself of an electronic device, including in terms of cost, and it is desirable to improve the functionality of the hardware using a simple method. Therefore, the applicant has attempted to improve the performance of the hardware by retrofitting a thin and small electronic device, such as a stick type, called a hardware booster. There is.

In this case, since the electronic device is retrofitted, it is required to be sufficiently small and thin so that it can be mounted even in a limited space. At the same time, as the performance of CPUs and the like increases, the amount of heat generated increases, and in order to withstand this, a more effective cooling structure for electronic components is required, especially for devices used in harsh environments such as those used in vehicles. However, in the method shown in Patent Document 1, the heat sink is placed inside the casing, so the cooling efficiency is poor, and the axial flow type unit, in which the blower blades and motor are assembled into a casing, has poor cooling efficiency. A fan device was used, making it difficult to downsize the entire system.

The present invention has been made in view of the above circumstances, and its purpose is to provide an in-vehicle electronic device that can achieve sufficient miniaturization while ensuring high cooling performance for electronic components inside the housing. It is in.

In order to achieve the above object, an in-vehicle electronic device (1) of the present invention is installed in a vehicle, and a circuit board (4) on which an electronic component (8) is mounted is placed in a housing (2). ), one wall of the housing includes a heat radiating part (10) for radiating heat from the electronic component, and a heat radiating part (10) for blowing air to the heat radiating part. An air blowing part (13) is provided, and the heat radiation part has a plurality of metal heat radiation fins (18) extending in the air blowing direction on the outer surface of the one wall part, and the heat radiation part has a plurality of metal heat radiation fins (18) extending in the air blowing direction, and is provided with an exhaust hole (21) located between the heat radiating part and the air blowing part for penetrating the one wall part and blowing air toward the heat radiation fin, and the blowing part includes: An intake hole (17) is formed in one wall of the casing, and a blower fan device (5) is provided on the inner surface of the one wall for sucking outside air from the intake hole and discharging it from the exhaust hole. It is arranged.

According to this, a heat dissipation section is partially provided on one wall of the casing, and the heat of the electronic component is transferred to metal heat dissipation fins provided on the outer surface of the one wall, thereby performing heat dissipation. . In this case, when the ventilation fan device is driven, outside air is sucked in through the intake hole provided in one wall of the housing, and air is drawn in from the air intake hole provided in one wall of the housing, and the air is drawn in between the heat radiation part and the ventilation part of one wall of the housing. It is discharged as cooling air from the exhaust hole. The discharged cooling air can be directly applied to the radiation fins exposed on the outside of the housing, and the cooling air passes through the radiation fins to radiate heat to the outside, in other words, to cool the electronic components. . Thereby, a high cooling effect can be obtained by heat radiation from the radiation fins of the heat radiation part and air blowing by the ventilation fan device.

At this time, one wall of the housing itself functions as a heat sink with radiation fins, which reduces the number of parts and saves space compared to when the housing and heat sink are provided separately. can be achieved. In addition, an air intake hole is formed in the air blowing section provided on one wall of the housing, and a blowing fan device is provided inside the air intake hole, so that one wall of the housing forms at least a part of the fan casing. It will be in the form of Therefore, compared to a fan device having a separate fan casing, the fan device can be made smaller and thinner. As a result, it is possible to realize sufficient downsizing while ensuring high cooling performance for the electronic components inside the casing. Further, the air generated by the blower fan device is discharged from the exhaust hole without passing through the circuit board.

A perspective view showing an external appearance of an in-vehicle electronic device, showing one embodiment. Exploded perspective view of in-vehicle electronic device Longitudinal cross-sectional view along line II in Figure 1 A perspective view showing a half of the in-vehicle electronic device cut along line II in FIG. A perspective view showing the half part from a direction different from that in FIG. 4. Perspective view of the casing from the back side Perspective view of the housing from a different direction from Figure 1

Hereinafter, the drawings will be described about an embodiment applied to a small electronic device called a hardware booster, which is used as an in-vehicle electronic device, for example, to update an automobile ECU (Electronic Control Unit) by retrofitting it. This will be explained with reference to. An in-vehicle electronic device 1 (hereinafter simply referred to as "electronic device 1") according to the present embodiment is mounted, for example, in an instrument panel portion of an automobile. When actually installed in a vehicle, the side with the intake hole of the casing may face downward, but in the drawings and the following explanation, for convenience, the intake hole is on the top side of the casing, and the side with the intake hole facing downward in the longitudinal direction. The state shown in FIG. 3 will be described as a longitudinal sectional front view.

1 and 2 schematically show the overall external configuration of an electronic device 1 according to this embodiment. This electronic device 1 is constructed by incorporating a circuit board 4, a blower fan device 5, etc. into a case composed of a housing 2 and a cover 3. The housing 2 has a thin rectangular box shape that is open at the bottom in the figure and is thin in the vertical direction and slightly elongated in the left and right directions in the figure. In this embodiment, the housing 2 is entirely made of metal, and is manufactured, for example, by aluminum die casting. The detailed configuration of this housing 2 will be described later.

The cover 3 is made of plastic, for example, and has a rectangular plate shape that closes the lower opening of the housing 2 . At the center of each of the four sides of the cover 3, an engaging piece 6 is integrally provided so as to rise upward in the figure. A rectangular engagement hole 6a is formed in this engagement piece portion 6, and an engagement claw 7 formed on the side surface of the housing 2 elastically engages with the engagement hole 6a. ing. Thereby, the housing 2 and the cover 3 are removably coupled. Incidentally, in this embodiment, as shown in FIG. 1, the outer width dimension W of the entire case is, for example, 80 mm, the depth dimension D is, for example, 45 mm, and the height dimension H is, for example, about 15 mm.

The circuit board 4 has a horizontally elongated shape, as shown in FIG. A plurality of electronic components including a CPU 8 are mounted on the upper surface of this circuit board 4 to form an electric circuit. The CPU 8 is mounted near the right end of the circuit board 4 in the figure. The CPU 8 is considered to generate a large amount of heat, and is a component that requires effective cooling using a cooling structure described below. The upper surface of the CPU 8 serves as a heat dissipation surface, and is thermally connected to a heat sink 10 as a heat dissipation portion of the casing 2, which will be described later, via a heat dissipation gel 9 made of silicon, for example.

At this time, as partially shown in FIGS. 2 and 3, the circuit board 4 is directly attached to a mounting portion provided on the housing 2. That is, four corner portions of the circuit board 4 are formed with screw insertion holes 4a. On the other hand, as partially shown in FIG. 6, on the lower surface side of the upper wall of the housing 2, there are four screw boss portions 11 as attachment portions corresponding to the screw insertion holes 4a. It is integrally provided so as to extend downward. The circuit board 4 is now attached to the housing 2 by passing the four screws 12 through the screw insertion holes 4a from the bottom side and tightening them to the screw bosses 11. Although not shown, the circuit board 4 is provided with, for example, a USB standard connector for external connection, facing an opening provided on, for example, the left side wall of the housing 2. That is, a connection is made with the existing ECU in the vehicle.

The ventilation fan device 5 is for cooling the CPU 8 and the like, and in this embodiment, a centrifugal fan is employed. The blower fan device 5 is installed in a blower section 13 provided above the circuit board 4 on the left side of the housing 2 in the figure. This blower fan device 5 includes a centrifugal impeller 14, a fan motor (not shown) consisting of, for example, a DC brushless motor for rotationally driving the impeller 14, a scroll casing 15 (see FIG. 6) surrounding the impeller 14, etc. It consists of At this time, as will be described later, the impeller 14 is rotatably supported by a bearing portion 16 that is integrally provided in the housing 2 together with the scroll casing 15, with the axial direction being the vertical direction.

As shown in FIGS. 3 and 5, the blower fan device 5 blows air in the axial direction, that is, in the direction of arrow A from the upper surface side of the housing 2, by rotating the impeller 14 by driving the fan motor. It is configured to suck in air, generate cooling air, and discharge it in a radial direction, in this case to the right in the figure. In this case, air is blown in the direction of arrow B from left to right in the figure, and that direction is defined as the air blowing direction. Therefore, the air blower 13 is provided upstream of the heat sink 10 in the air blowing direction.

Now, the configuration of the casing 2 will be explained with reference also to FIGS. 3 to 7. FIG. 6 shows the case 2 with the impeller 14 attached and turned upside down, and FIG. 7 shows the case 2 from a different direction from FIGS. 1 and 2. . As described above, the housing 2 is integrally molded, for example, by aluminum die-casting, into a thin rectangular box shape with an open bottom surface, and the heat sink 10 as a heat dissipation part is integrally provided on the right side in the figure. A blower section 13 is provided on the left side in the figure.

In the air blowing section 13, an air intake hole 17 for sucking outside air by the air blowing fan device 5 is formed vertically through an upper wall portion of the housing 2. This intake hole 17 corresponds to the impeller 14, and has four narrow arc-shaped holes lined up at intervals to form a circular shape, and is formed double inside and outside. has been done. Further, as shown in FIG. 6 and the like, the scroll casing 15 is integrally provided at the lower part of the upper wall portion of the housing 2. As shown in FIG. The scroll casing 15 is constructed by surrounding the front, rear, and left sides of the impeller 14 in a curved shape with small gaps, and providing a thin wall that opens on the right side in the figure.

As shown in FIG. 4 and the like, a bearing portion 16 for supporting the impeller 14 is integrally provided on the lower surface side of the upper wall portion of the housing 2 at a position corresponding to the inner peripheral side of the intake hole 17. It is being Although not shown in detail, this bearing part 16 is provided in a cylindrical shape, and the shaft part of the impeller 14 is inserted into the center hole of the bearing part 16 to rotatably support it. The intake hole 17 is located so as to surround the outer circumferential side of the bearing section 16, and is therefore located between the heat sink 10 as a heat dissipation section and the bearing section 16.

On the other hand, as shown in FIG. 3, etc., the heat sink 10 provided on the right side of the housing 2 is located one step lower than the portion of the upper wall of the housing 2 that constitutes the ventilation section 13. A plurality of heat dissipating fins 18 extending in the left-right direction, that is, in the air blowing direction, are integrally formed on the upper surface of the horizontally provided upper wall portion. The position of the upper end of the radiation fin 18 and the upper surface of the air blower 13 are approximately at the same height. As shown in FIG. 6, a convex portion 19 located directly above the CPU 8 and slightly convex downward is provided on the lower surface of the upper wall portion constituting the heat sink 10. The heat dissipation gel 9 is provided between the upper surface of the CPU 8 and the upper surface of the CPU 8 .

As shown in FIGS. 3 and 4, the upper wall of the housing 2 is located between the air blower 14 and the heat sink 10 and is slightly inclined downward so as to be recessed inward, that is, downward. A falling wall 20 is integrally provided. This falling wall 20 faces the opening on the right side of the scroll casing 15, and is used as an exhaust for blowing cooling air from the air blowing section 13 toward the radiation fins 18. A hole 21 is provided through the hole 21 . As shown in FIG. 7, the exhaust hole 21 is located between the radiation fins 18 and opens. Further, this exhaust hole 21 is also located between the heat sink 10 and the bearing section 16.

Furthermore, as shown in FIGS. 3, 5, etc., on the upper wall of the casing 2, there is a slope extending from the lower end side of the exhaust guide surface 22 so as to gently rise toward the right. An exhaust guide surface 22 that continues to the upper wall of the heat sink 10 is provided. The radiation fins 18 are provided to extend to the upper surface of the exhaust guide surface 22. Further, the base end, that is, the lower end side of the exhaust guide surface 22 is located near the upper surface of the circuit board 4. At this time, although not shown, it is also possible to provide a closing member made of an elastic material such as sponge or rubber at the lower end of the exhaust guide surface 22 so as to be in contact with the upper surface of the circuit board 4.

With this, by driving the blower fan device 5, the cooling air from the blower section 13 is discharged to the right from the exhaust hole 21, as shown by arrow B, without almost passing over the upper surface of the circuit board 4. Air is blown between the radiation fins 18 on the upper surface of the heat sink 10 while flowing on the upper surface of the exhaust guide surface 22 . As described above, the casing 2 is further provided with a screw boss 11 integrally located on the lower surface side of the upper wall, and is located on the side wall and has a screw boss 11 for connecting the engaging pawl 7 and the connector. An opening is also provided.

Next, the functions and effects of the electronic device 1 configured as described above will be described. The electronic device 1 having the above configuration is mounted on an instrument panel portion of, for example, an ECU for an automobile in order to update hardware resources as a retrofit. This type of electronic device 1 is required to be sufficiently miniaturized so that it can be mounted even in a narrow space. A higher cooling effect is required for the CPU 8, which is a heat generating component mounted on the CPU 8.

In the above configuration, heat generated by the CPU 8 on the circuit board 4 is transmitted from the convex portion 19 to the heat sink 10 on the upper wall of the housing 2 via the heat dissipation gel 9, and is radiated from the heat dissipation fins 18. be exposed. At this time, by driving the ventilation fan device 5, outside air is sucked in from the intake hole 17 provided in the upper wall of the housing 2, as shown by arrow A in FIG. 3, etc., and as shown by arrow B. Then, the cooling air is discharged from the exhaust hole 21 located between the heat sink 10 and the sending section 13. The cooling air discharged from the exhaust hole 21 passes through the exhaust guide surface 22 and directly hits the radiation fins 18, and as the cooling air passes through the radiation fins 18, heat is radiated to the outside. Thereby, a high cooling effect of the CPU 8 can be obtained by heat radiation from the radiation fins 18 of the heat sink 10 and air blowing by the ventilation fan device 5.

At this time, the upper wall of the casing 2 itself functions as a heat sink 10 having radiation fins 18, which reduces the number of parts and saves space compared to the case where the casing 2 and the heat sink are provided separately. It is possible to aim for In addition, an air intake hole 17 is formed in the air blowing part 13 provided on the upper wall of the housing 2, and the air blowing fan device 5 is provided inside the air intake hole 17, so that a part of the housing 2 is at least the fan casing. It will form a part of it. Therefore, the fan casing can be made smaller and thinner than when the fan casing is provided separately. As a result, according to the present embodiment, it is possible to obtain the excellent effect that sufficient miniaturization can be achieved while ensuring high cooling performance for the CPU 8 inside the housing 2.

In particular, in this embodiment, the entire housing 2 is made of metal, in this case aluminum, so that the radiation fins 18 are provided integrally with the housing 2. This makes it easy to integrally provide the radiation fins 18, and it is possible to improve the heat radiation effect by increasing the thermal conductivity of the heat sink 10. Further, in this embodiment, the cooling air generated by the blower fan device 5 is discharged from the exhaust hole 21 without passing through the circuit board 4 . This makes it possible to prevent condensation from occurring due to exposure of the relatively low-temperature circuit board 4 to the relatively low-temperature circuit board 4 when the outside air is highly humid.

In this embodiment, the exhaust hole 21 is provided so as to open toward the radiation fin 18 side, and the exhaust hole 21 is provided on the outer surface of the upper wall of the housing 2 and extends in an inclined shape from the exhaust hole 21 toward the radiation fin 18. The configuration is such that a guide surface 22 is provided. As a result, the cooling air discharged from the exhaust hole 21 flows along the exhaust guide surface 22 extending in an inclined shape, so that the cooling air flows smoothly while maintaining the wind speed, and is supplied to the radiation fin portion 18 portion. Therefore, it becomes possible to more efficiently radiate heat using the cooling air.

Further, in this embodiment, the blowing section 13 of the housing 2 is configured to be integrally provided with a bearing section 16 that rotatably supports the impeller 14 of the blowing fan device 5. As a result, the number of parts can be reduced, the configuration of the blower fan device 5 can be simplified, and the overall size can be reduced, compared to the case where the bearing section is provided separately. Moreover, a scroll casing 15 that surrounds an impeller 14 is integrally provided in the blower section 13 of the housing 2. As a result, the scroll casing, which is normally provided separately, is integrated into the housing 2, thereby further reducing the number of parts, simplifying the configuration of the 5 parts of the blower fan device, and ultimately reducing the overall size. be able to.

At this time, when the bearing part 16 is integrally provided in the housing 2 as described above, the heat of the heat sink 10 portion is transferred to the blower part 13 and then to the bearing part 16. There is a possibility that this may cause adverse effects such as deformation of the bearing portion 16 and deterioration of the support accuracy of the impeller 14. However, in this embodiment, part of the exhaust hole 21 and the intake hole 17 are provided in the upper wall of the housing 2 so as to be located between the heat sink 10 and the bearing part 16. As a result, the exhaust hole 21 and the intake hole 17 serve as resistance to heat transfer from the heat sink 10 to the bearing section 16, so that it is possible to suppress the heat of the heat sink 10 from having an adverse effect on the bearing section 16. .

Further, in this embodiment, the circuit board 4 is configured to be directly attached to a screw boss portion 11 as an attachment portion provided on the housing 2. This facilitates dimensional control between the heat dissipation surface of the CPU 8 on the circuit board 4 and the lower surface of the heat sink 10, in this case the protrusion 19, of the housing 2, which is effective in increasing the heat transfer effect. At this time, the convex portion 19 on the lower surface of the heat sink 10 is placed directly above the CPU 8 with a gap, and the heat dissipation gel 9 is placed in the gap, so it is easy to reduce the gap and the heat sink 10 is connected to the CPU 8. The heat transfer effect via the heat dissipation gel 9 and the cooling effect of the CPU 8 can be enhanced.

Although not described in detail in the above embodiment, the proximal end, that is, the lower end side of the exhaust guide surface 22 is arranged near the upper surface of the circuit board 4, and there is a closing member that closes the gap therebetween. can be provided. According to this, the cooling air generated by the blower fan device 5 can efficiently flow from the exhaust hole 21 to the exhaust guide surface 22 without flowing along the circuit board 4. At the same time, the effect of preventing dew condensation caused by the flow of cooling air on the surface of the circuit board 4 can be further enhanced. By employing a cushioning material such as sponge or rubber for the closing member, dimensional errors can be absorbed, making it more effective.

Further, in the above embodiment, when attaching the circuit board 4 to the casing 2, a configuration is adopted in which the circuit board 4 is screwed to the screw boss portion 11, but various configurations such as engagement can be adopted. In the above embodiment, the entire casing 2 is made of aluminum die-casting, but it is also possible to make changes such as making only the heat dissipation part made of metal and the remaining part made of synthetic resin. In the above embodiment, the cover 3 is made of synthetic resin, but it may be made of metal such as sheet metal or die casting. In the above embodiment, a centrifugal fan is used as the blower fan device 5, but other fan devices such as an axial fan can also be used. In this case, a configuration may be adopted in which a guide wall is provided on the discharge side of the axial fan to guide air toward the heat radiation section. The bearing portion and the scroll casing portion may be provided separately from the housing 2.

In addition, in the above embodiment, the present invention is applied to an electronic device for retrofitting called a hardware booster for improving the performance of hardware, but it can be applied to electronic devices for various uses and types of vehicles in general. It is possible to apply it to Of course, various changes can be made to the overall shape of the casing, the arrangement of the connectors, etc. Although the present disclosure has been described based on examples, it is understood that the present disclosure is not limited to the examples or structures. The present disclosure also includes various modifications and equivalent modifications. In addition, various combinations and configurations, as well as other combinations and configurations that include only one, more, or fewer elements, are within the scope and scope of the present disclosure.

In the drawings, 1 is an in-vehicle electronic device, 2 is a housing, 3 is a cover, 4 is a circuit board, 5 is a blower fan device, 8 is a CPU (electronic component), 9 is a heat dissipation gel, and 10 is a heat sink (heat dissipation part) , 11 is a screw boss part (mounting part), 13 is a blower part, 14 is an impeller, 15 is a scroll casing, 16 is a bearing part, 17 is an intake hole, 18 is a radiation fin, 21 is an exhaust hole, 22 is for exhaust Indicates the guide surface.

Claims (9)

An electronic device (1) mounted on a vehicle,
It is configured by housing a circuit board (4) on which an electronic component (8) is mounted in a housing (2),
A heat radiating part (10) for radiating heat from the electronic component and a blowing part (13) for blowing air to the heat radiating part are provided on one wall of the casing,
The heat radiation part has a plurality of metal heat radiation fins (18) extending in the air blowing direction on the outer surface of the one wall part,
An exhaust hole (21) is provided in one wall of the housing, located between the heat radiating section and the air blowing section, for penetrating the one wall and blowing air toward the heat radiating fins. ,
The air blowing section has an air intake hole (17) formed in one wall of the housing, and an air blower that sucks in outside air from the air intake hole and discharges it from the exhaust hole on the inner surface side of the one wall. A fan device (5) is installed,
In the in-vehicle electronic device, air generated by the blower fan device is discharged from the exhaust hole without passing through the circuit board . 2. The in-vehicle electronic device according to claim 1, wherein the entire housing is made of metal, and the radiation fins are integrally provided. The exhaust hole is opened at a position recessed inwardly between the heat radiating part and the air blowing part in one wall of the casing and facing the heat radiating fin side,
3. The in-vehicle electronic device according to claim 1 , wherein an exhaust guide surface (22) extending obliquely from the exhaust hole toward the radiation fin is provided on an outer surface of one wall of the housing. 4. The in-vehicle electronic device according to claim 3 , wherein a base end of said exhaust guide surface is located near said circuit board, and a closing member is provided to close a gap therebetween. 5. The blower according to claim 1, wherein the blower section of the housing is integrally provided with a bearing section (16) that rotatably supports an impeller (14 ) of the blower fan device. Automotive electronic equipment. 6. The vehicle-mounted electronic device according to claim 5 , wherein at least a portion of the exhaust hole and the intake hole are provided in one wall of the casing so as to be located between the heat radiating section and the bearing section. The in-vehicle electronic device according to any one of claims 1 to 6 , wherein a scroll casing (15) is integrally provided in the ventilation section of the housing so as to surround an impeller of the ventilation fan device. . The in-vehicle electronic device according to any one of claims 1 to 7 , wherein the circuit board is directly attached to a mounting portion (11) provided on the casing. The in-vehicle electronic device according to any one of claims 1 to 8 , wherein the heat dissipation part of the casing is disposed directly above the electronic component with a gap, and a heat dissipation gel (9) is disposed in the gap.

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