JP7565804B2 - Heat dissipation structure - Google Patents

Description

The present invention relates to a heat dissipation structure.

A cooling technique is disclosed in Japanese Patent Application Laid-Open No. 2003-233663.
In the abstract of Patent Document 1, the "Problem" section states, "To make it possible to perform cooling treatment on a heat source device more appropriately and efficiently." The "Solution" section states, "A small heat source 3 with a small amount of heat generation, a large heat source 4 with a large amount of heat generation, a ventilation duct 5 that sends air through the small heat source 3 toward the large heat source 4, and a fan device 6 that generates an air flow in the ventilation duct 5 are disposed in a given device body 2, and the fan device 6 is configured to include a small-capacity fan device 6a provided upstream of the small heat source 3 in the ventilation duct 5, and a large-capacity fan device 6b provided upstream of the large heat source 4 in the ventilation duct."

JP 2009-86218 A

Patent Document 1 requires the installation of two fans: a fan (small-capacity fan unit 6a) that draws in outside air into the device body 2, and a fan (large-capacity fan unit 6b) that stirs up air inside the device body 2.

The present invention aims to provide a heat dissipation structure that can more efficiently dissipate heat from multiple heat sources with different heat values.

One aspect of the present invention is a heat dissipation structure comprising a housing having an intake port for taking in air and an exhaust port for exhausting air, a fan, a first radiator for dissipating heat generated by a first heat source, and a second radiator for dissipating heat from a second heat source that generates a greater amount of heat than the first heat source, wherein the internal space of the housing includes a first space connected to the intake port and in which the first radiator is provided, and a second space connected to the exhaust port and in which the second radiator is provided, the fan is disposed at a point where the first space and the second space are connected, and flows air from the first space to the second space, the second radiator and a surface of the housing form a duct extending between the fan and the exhaust port, the second space is formed by the duct, and the opening area of the exhaust port is smaller the closer it is to the fan .

The present invention allows multiple heat sources with different heat values to dissipate heat more efficiently.

1 is a perspective view of an in-vehicle device according to an embodiment of the present invention, as viewed from the front side. FIG. 2 is a perspective view of the in-vehicle device as seen from the rear side. 2 is a plan view of the bottom surface of the housing of the in-vehicle device. FIG. FIG. 2 is a perspective view showing the internal structure of a housing. 1 is a conceptual diagram of a heat dissipation structure provided in an in-vehicle device. 4 is a cross-sectional view taken along line AA in FIG. 3. 4 is a cross-sectional view taken along line BB in FIG. 3. FIG. 2 is a perspective view showing a configuration of a second heat sink and a fan device. FIG. 11 is a plan view showing the bottom surface of an in-vehicle device according to a second embodiment of the present invention. FIG. 2 is a plan view of the in-vehicle device as seen from the rear. 2 is a diagram showing the internal structure of the in-vehicle device with the top surface of the housing removed. FIG. This is a cross-sectional view taken along line CC in Figure 11.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[First embodiment]
Fig. 1 is a perspective view of the front side of an in-vehicle device 1 according to this embodiment. Fig. 2 is a perspective view of the rear side of the in-vehicle device 1.
The in-vehicle device 1 shown in these figures is an example of an in-vehicle device called an IVI (In-Vehicle Infotainment) device. As shown in Fig. 1, the in-vehicle device 1 includes a substantially box-shaped (i.e., six-sided) housing 2 that constitutes the exterior of the device.
The vehicle in which the in-vehicle device 1 is installed has an instrument panel, which is a type of interior material, and an installation bracket is provided on the instrument panel. The housing 2 of the in-vehicle device 1 is attached to the installation bracket with the front surface 2A facing the interior of the vehicle. In the in-vehicle device 1 of this embodiment, both side surfaces 2B, 2B of the housing 2 are fixed to the installation bracket by appropriate fixing members.
As shown in FIG. 2, the in-vehicle device 1 also includes a large number of different connectors 6 for connecting various wires. These connectors 6 are provided on the rear surface 2C of the housing 2.

FIG. 3 is a plan view of the bottom surface 2D of the housing 2 of the in-car device 1. FIG.
2 and 3, the housing 2 includes an intake section 10 that takes in air from the outside to the inside, and an exhaust section 12 that exhausts air from the inside to the outside, and these intake section 10 and exhaust section 12 are provided on the bottom surface 2D of the housing 2. The intake section 10 and exhaust section 12 are respectively composed of a number of intake ports 10A and a number of exhaust ports 12A provided on the bottom surface 2D. Furthermore, in the in-car device 1 of this embodiment, exhaust ports 12A are also provided on the back surface 2C.

By providing the intake section 10 (intake port 10A) and the exhaust section 12 (exhaust port 12A) on the bottom surface 2D, it is more difficult for water and dust to enter the interior of the housing 2 than in a configuration in which they are provided on the top surface 2E (Figure 1) of the housing 2.
Furthermore, because various components (e.g., connector 6, components for fixing to the mounting bracket, etc.) are arranged on front surface 2A, both side surfaces 2B, 2B, and rear surface 2C, the space and positions allocated to intake section 10 and exhaust section 12 are limited. In particular, because the fixing positions to the mounting bracket differ depending on the vehicle model, etc., it is difficult to provide intake section 10 and exhaust section 12 on side surface 2B. In contrast, fewer components are arranged on bottom surface 2D compared to other surfaces, so it is easy to provide intake port 10A and exhaust port 12A with an opening area that can obtain sufficient intake and exhaust volumes in relatively free positions.

Fig. 4 is a perspective view showing the internal structure of the housing 2 of the in-vehicle device 1. Fig. 5 is a conceptual diagram of a heat dissipation structure 20 provided in the in-vehicle device 1. Note that Fig. 5 is drawn for the purpose of making it easier to understand the configuration of the heat dissipation structure 20, and the dimensions and orientations of each member are different from those of other drawings.
As shown in Figure 5, the in-vehicle device 1 is provided with a first radiator 30 in the internal space S of the housing 2 that radiates heat generated by a first heat source D1, and a second radiator 32 that radiates heat from a second heat source D2 that has a greater heat generation amount than the first heat source D1.
Each of the first heat source D1 and the second heat source D2 includes one or more heat-generating components 40, and the heat values of the first heat source D1 and the second heat source D2 are the total amounts of heat generated by the heat-generating components 40 included therein. The heat-generating components 40 are typically electric and electronic components.

The heat dissipation structure 20 is a structure that recovers heat from the first heat sink 30 and the second heat sink 32 using one fan 35, and efficiently dissipates heat from the first heat source D1 and the second heat source D2.
Specifically, as shown in FIG. 5 , the heat dissipation structure 20 includes a housing 2 having the above-mentioned intake section 10 (intake port 10A) and exhaust section 12 (exhaust port 12A), a fan 35, the above-mentioned first heat sink 30, and a second heat sink 32.
The housing 2 has an internal space S which includes a first space S1 connected to the intake section 10 and in which a first heat sink 30 is provided, and a second space S2 connected to the exhaust section 12 and in which a second heat sink 32 is provided.
The fan 35 is disposed at a location in the internal space S of the housing 2 where the first space S1 and the second space S2 are connected, and is configured to send air from the first space S1 to the second space S2.
When the fan 35 operates, an airflow E is generated in the internal space S of the housing 2, passing through the intake section 10, the first space S1, the fan 35, the second space S2, and the exhaust section 12 in this order.
Then, the heat generated by the first heat source D1 and the second heat source D2 is recovered by the airflow E from the first heat radiator 30 in the first space S1 and the second heat radiator 32 in the second space S2, respectively, thereby dissipating heat from the first heat source D1 and the second heat source D2.

With this heat dissipation structure 20, the fan 35 does not need to have either the suction surface or the discharge surface directly facing the outside, and so can be placed without being restricted to a position that contacts the exterior surfaces of the housing 2 (front surface 2A, rear surface 2C, side surface 2B, bottom surface 2D, top surface 2E). Therefore, the placement position of the fan 35 can be appropriately set within the internal space S of the housing 2 according to the shapes and positions of the first space S1 and the second space S2, increasing the degree of freedom in the layout within the internal space S.

In addition, since the heat dissipation from the first heat source D1 and the second heat source D2 is performed separately by the first heat sink 30 and the second heat sink 32, it is easy to ensure the heat resistance of the heat-generating components 40 included in the first heat source D1 and the second heat source D2.
More specifically, an IVI device, which is an example of the in-vehicle device 1, typically includes components with relatively low power consumption (hereinafter referred to as "low power consumption components") and components with relatively high power consumption (hereinafter referred to as "high power consumption components"). The low power consumption components are, for example, heat-generating components 40 such as a CPU (Central Processing Unit) or a memory device, which generate a relatively small amount of heat and have a relatively low heat resistance. The high power consumption components are, for example, components that constitute an audio amplifier or heat-generating components 40 that constitute a power supply, which have a relatively high output, a relatively large amount of heat, and a relatively high heat resistance.

In the heat dissipation structure 20 of this embodiment, the low power consumption components are included in the first heat source D1, and the high power consumption components are included in the second heat source D2, and the heat dissipation paths between these low power consumption components and high power consumption components are thermally separated. This makes the low power consumption components less susceptible to the effects of the large heat generated by the high power consumption components, making it easier to ensure the heat resistance of the low power consumption components.

In the heat dissipation structure 20, the first radiator 30, which radiates heat from the first heat source D1, which has a relatively small amount of heat generation, is located upstream of the airflow E, so that the heat of the first heat source D1 is recovered by the air immediately after it is taken in from the intake section 10. Since the temperature of this air is lower than the air downstream of the airflow E, it is possible to dissipate heat from the first heat source D1 more efficiently than in a configuration in which the first radiator 30 is located downstream.
Furthermore, since the temperature of the air passing through the fan 35 is kept lower than in a configuration in which the second radiator 32, which radiates heat from the second heat source D2, is positioned upstream of the airflow E, the thermal stress applied to the fan 35 is reduced, and deterioration over time due to the thermal stress is reduced.

Next, the configuration of the heat dissipation structure 20 included in the in-vehicle device 1 of this embodiment will be described in more detail.
6 and 7 are cross-sectional views showing the internal structure of the in-vehicle device 1. FIG. 6 is a cross-sectional view taken along line AA in FIG. 3, and FIG. 7 is a cross-sectional view taken along line BB in FIG.
The first heat source D1 includes one or more of the above-mentioned heat generating components 40 (the above-mentioned low power consumption components) and a mounting board 42 on which the heat generating components 40 are mounted.
The first heat sink 30 is positioned in a position where the heat-generating component 40 is sandwiched between it and the mounting board 42, and is thermally coupled to the heat-generating component 40, thereby transferring heat from the heat-generating component 40 and dissipating the heat into the first space S1.

The first heat sink 30 of the present embodiment is a substantially plate-shaped member made of a highly thermally conductive material (e.g., a metal material). One surface 30A of the first heat sink 30 is thermally coupled to the heat generating component 40, and the other surface 30B is disposed facing the intake section 10.
More specifically, as shown in FIG. 7 , the first heat sink 30 has a recessed portion 33 that is recessed from the other surface 30B toward one surface 30A, and the recessed portion 33 comes into contact with the heat-generating component 40 on one surface 30A, thereby thermally coupling the heat-generating component 40 to the one surface 30A.

As shown in Figures 6 and 7, the first space S1 is formed by a gap between the other surface 30B of the first heat sink 30 and the bottom surface 2D on which the intake section 10 (intake port 10A) is provided.
According to this configuration, the first radiator 30 of the first heat source D1 faces the intake section 10 (intake port 10A) and is directly exposed to air taken in from the outside, so that the heat generated by the first heat source D1 is efficiently recovered.

6, the second heat source D2 includes one or more heat-generating components 40 (the above-mentioned high power consumption components) and a mounting board 42 on which the heat-generating components 40 are mounted. In this embodiment, the heat-generating components 40 of the second heat source D2 are mounted on the mounting board 42 included in the first heat source D1, but may be mounted on a mounting board different from that of the first heat source D1.
The second heat sink 32 is positioned in a position where the heat-generating component 40 is sandwiched between it and the mounting board 42 of the second heat source D2, and is thermally coupled to the heat-generating component 40, so that heat is transferred from the heat-generating component 40 and dissipated into the second space S2.

FIG. 8 is a perspective view showing the configuration of the second heat radiator 32 and the fan 35. As shown in FIG.
The second heat sink 32 is a plate-like member formed from a material with high thermal conductivity (e.g., a metal material) and has the fan 35 attached to one end 47A via a mounting member 60 described later. As shown in Fig. 6, one surface 32A of the second heat sink 32 is thermally coupled to the heat-generating component 40, and the other surface 32B is disposed to face the exhaust section 12 (exhaust port 12A: Fig. 7).

In the heat dissipation structure 20 of this embodiment, the second heat sink 32 and the bottom surface 2D of the housing 2 form a duct 70 that extends between the fan 35 and the exhaust section 12 (exhaust port 12A), and the second space S2 is formed by this duct 70.

More specifically, as shown in Figures 6, 7, and 8, the second heat sink 32 has a pair of side walls 50, 50 extending from one end 47A to the other end 47B, and these side walls 50, 50 are provided on the other surface 32B (in the illustrated example, the edge of the other surface 32B). The pair of side walls 50 are formed at a height that contacts the bottom surface 2D of the housing 2, and a straight duct 70 is formed by the pair of side walls 50 and the other surface 32B of the second heat sink 32 and the bottom surface 2D of the housing 2.

With this configuration, the airflow E generated by the fan 35 passes through the inside of the duct 70 (the second space S2) and flows from one end 47A to the other end 47B of the second heat sink 32, so that the heat of the second heat source D2 can be efficiently recovered from the second heat sink 32, and the air discharged by the fan 35 (air whose heat has been recovered in the first space S1) does not circulate back into the internal space S of the housing 2.

In addition, in the heat dissipation structure 20 of this embodiment, the second radiator 32 is provided on the other surface 46 as shown in FIG. 8, and is provided with a plurality of plate-shaped fins 48 that protrude into the duct 70, and these fins 48 enhance the heat recovery efficiency. Furthermore, the fins 48 extend from one end 47A to the other end 47B (from the fan 35 side to the exhaust port 12A side) and are provided with gaps between each other, and function as a straightening plate that straightens the airflow E from one end 47A to the other end 47B. This makes it possible to suppress unevenness in heat recovery in the range from one end 47A to the other end 47B, and to efficiently dissipate heat from the second heat source D2.

Furthermore, in the exhaust section 12 provided on the bottom surface 2D, as shown in FIG. 3, the opening area of the exhaust port 12A is smaller at the exhaust port 12A provided at position Pa closer to the fan 35 than at the exhaust port 12A provided at position Pb farther from the fan 35. This reduces the amount of air exhausted to the outside at the one end 47A side of the duct 70, and maintains a sufficient flow rate at the other end 47B side, thereby preventing a decrease in heat dissipation capacity at the other end 47B side.

The mounting member 60 described above is a member for mounting the fan 35 to one end 47A of the second radiator 32. This mounting member 60 has an air guide passage 61 that connects the duct 70 and the discharge side of the fan 35, and the air discharged from the fan 35 is guided to the duct 70 through the air guide passage 61.

In the heat dissipation structure 20 of this embodiment, the second space S2 (the internal space of the duct 70) is formed with a smaller volume than the first space S1, and the airflow E flowing through the second space S2 is at a higher pressure and flow rate than the first space S1. This prevents the air that has recovered heat in the first space S1 from decreasing the heat recovery efficiency in the second space S2, and allows the second heat source D2, which has a relatively large heat generation amount, to sufficiently dissipate heat.

As explained above, this embodiment provides the following advantages:

In the heat dissipation structure 20 of this embodiment, the internal space S of the housing 2 includes a first space S1 connected to the air intake 10A of the housing 2 and in which a first heat sink 30 is provided, and a second space S2 connected to the air exhaust 12A of the housing 2 and in which a second heat sink 32 is provided, and a fan 35 is positioned at the location where the first space S1 and the second space S2 are connected, and flows air from the first space S1 to the second space S2.
Furthermore, a duct 70 extending between the fan 35 and the exhaust port 12A is formed by the second radiator 32 and the bottom surface 2D of the housing 2, and this duct 70 forms the second space S2.

According to this configuration, the first radiator 30, which radiates heat from the first heat source D1, which has a relatively small amount of heat generation, is located upstream of the airflow E generated by the operation of the fan 35, so that the first heat source D1 can be radiated heat more efficiently than in a configuration in which the first radiator 30 is located downstream.
In addition, since the airflow E generated by the fan 35 flows through the inside of the duct 70 (the second space S2), the heat of the second heat source D2 can be efficiently recovered from the second radiator 32, and the air discharged by the fan 35 (the air whose heat has been recovered in the first space S1) does not circulate back into the internal space S of the housing 2.
Furthermore, since neither the suction surface nor the discharge surface of the fan 35 needs to directly face the outside, the fan 35 can be disposed without being restricted to a position in contact with the exterior surface of the housing 2 .
In addition, since the heat dissipation of the first heat source D1 and the second heat source D2 is performed separately by the first heat sink 30 and the second heat sink 32, it becomes easier to ensure the heat resistance of the heat-generating components 40 included in the first heat source D1 and the second heat source D2.
In addition, the temperature of the air passing through the fan 35 is kept lower compared to a configuration in which the second radiator 32, which radiates heat from the second heat source D2, is positioned upstream of the airflow E, thereby reducing thermal stress on the fan 35 and preventing deterioration over time due to the thermal stress.

In the heat dissipation structure 20 of the present embodiment, the first heat dissipator 30 is disposed to face the air intake port 10A.
As a result, the first radiator 30 is directly exposed to air taken in from the outside, so that the amount of heat generated by the first heat source D1 can be efficiently recovered.

In the heat dissipation structure 20 of this embodiment, the second heat dissipator 32 is provided with a plurality of fins 48 that protrude into the duct 70, so that the efficiency of heat recovery from the second heat dissipator 32 can be improved.

In this embodiment, the heat dissipation structure 20 has a smaller opening area for the exhaust port 12A closer to the fan 35, so a sufficient amount of air can flow within the duct 70 to positions far from the fan 35.

In the heat dissipation structure 20 of the present embodiment, the volume of the second space S2 is smaller than the volume of the first space S1.
As a result, the air flow E flowing through the second space S2 becomes higher pressure and faster than the first space S1, and even if the air has recovered heat in the first space S1, the reduction in the heat recovery efficiency in the second space S2 due to the air is suppressed, and the second heat source D2, which has a relatively large heat generation amount, can be sufficiently dissipated.

[Second embodiment]
In the heat dissipation structure 20 of the first embodiment, the duct 70 is configured by the second heat sink 32 and the bottom surface 2D of the housing 2. In the present embodiment, a heat dissipation structure 120 will be described in which the duct 70 is configured by the second heat sink 32 and the top surface 2E of the housing 2. In the present embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

Fig. 9 is a plan view of the bottom surface 2D of the in-vehicle device 100 according to this embodiment. Fig. 10 is a plan view of the back surface 2C of the in-vehicle device 100.
As shown in these figures, in the in-vehicle device 100, similarly to the first embodiment, the intake section 10 (intake port 10A) is provided on the bottom surface 2D of the housing 2. On the other hand, the exhaust section 12 (exhaust port 12A) is provided in a position closer to the top surface 2E inside the back surface 2C of the housing 2, rather than on the bottom surface 2D.

Fig. 11 is a diagram showing the internal structure of the in-car device 100 with the top surface 2E of the housing 2 removed. Fig. 12 is a cross-sectional view taken along line CC of Fig. 11.
11 and 12, in the heat dissipation structure 120 of the present embodiment, the heat-generating component 40 included in the second heat source D2 is mounted on the surface of the mounting board 42 facing the top surface 2E, unlike the first embodiment. The second heat sink 132 is disposed facing the top surface 2E, and contacts the heat-generating component 40 with a convex portion 136 protruding toward the bottom surface 2D.
As a result, the second heat sink 132 and the upper surface 2E of the housing 2 form a duct 170 extending between the fan 35 and the exhaust port 12A, and the duct 170 forms the second space S2.

In the heat dissipation structure 120 of this embodiment, the duct 170 (second space S2) has a smaller cross-sectional diameter on the exhaust port 12A side than on the fan 35 side, as shown in FIG. 12. This prevents a decrease in flow velocity in the duct 170 (second space S2) at locations far from the fan 35, thereby preventing a decrease in heat recovery efficiency at locations far from the fan 35.

The first and second embodiments described above merely show one aspect of the present invention, and can be modified and applied as desired without departing from the spirit and scope of the present invention.

[Modification of the first embodiment]
In the heat dissipation structure 20 of the first embodiment, similarly to the second embodiment, the exhaust section 12 (exhaust port 12A) may be provided only on the rear surface 2C, and the cross-sectional diameter of the duct 70 may become smaller the farther from the fan 35 .

[Modifications of the first and second embodiments]
The intake section 10 may be provided not only on the bottom surface 2D of the housing 2 but also on other surfaces such as the side surface 2B as appropriate.

The in-vehicle device 1, 100 is not limited to an IVI device. That is, the in-vehicle device 1, 100 may be an in-vehicle audio device, an in-vehicle audiovisual device, an in-vehicle navigation device, or a device that combines the functions of both a navigation device and an audio device.

[Other Modifications]
The heat dissipation structure of the present invention can be applied to any device that includes a first heat source D1 and a second heat source D2 inside a housing 2, and is not limited to an in-vehicle device.

In the above-described embodiments, the descriptions of directions such as horizontal and vertical, various numerical values, and shapes do not exclude the periphery of the direction, the periphery of the numerical values, and approximate shapes, unless otherwise specified. In other words, the directions, numerical values, and shapes in the embodiments include the periphery of the direction, the periphery of the numerical values, and approximate shapes (so-called equivalent ranges) as long as they provide the same action and effect as these directions, numerical values, and shapes.

Reference Signs List 1, 100 Vehicle-mounted device 2 Housing 2A Front surface 2B Side surface 2C Rear surface 2D Bottom surface 2E Top surface 10 Intake section 10A Intake port 12 Exhaust section 12A Exhaust port 20, 120 Heat dissipation structure 30 First heat sink 32, 132 Second heat sink 35 Fan 40 Heat-generating component 42 Mounting board 48 Fin 60 Mounting member 61 Air guide path 70, 170 Duct D1 First heat source D2 Second heat source E Air flow S Internal space S1 First space S2 Second space

Claims (6)

A housing provided with an intake port for taking in air and an exhaust port for discharging air;
With fans,
a first radiator that radiates heat generated by the first heat source;
a second radiator configured to radiate heat from a second heat source having a larger heat generation amount than the first heat source;
Equipped with
The internal space of the housing is
a first space connected to the intake port and in which the first radiator is provided;
a second space connected to the exhaust port and in which the second radiator is provided;
Including,
The fan is
The air conditioner is disposed at a location where the first space and the second space are connected to each other, and causes air to flow from the first space to the second space;
the second radiator and a surface of the housing form a duct extending between the fan and the exhaust port, and the second space is formed by the duct;
The opening area of the exhaust port is smaller as it is closer to the fan.
A heat dissipation structure characterized by: A housing provided with an intake port for taking in air and an exhaust port for discharging air;
With fans,
a first radiator that radiates heat generated by the first heat source;
a second heat sink provided separately from the first heat sink and configured to radiate heat from a second heat source having a larger heat generation amount than the first heat source;
Equipped with
The internal space of the housing is
a first space connected to the intake port and in which the first radiator is provided;
a second space connected to the exhaust port and in which the second radiator is provided;
Including,
The fan is
The air conditioner is disposed at a location where the first space and the second space are connected to each other, and causes air to flow from the first space to the second space;
The second radiator and a surface of the housing form a duct extending between the fan and the exhaust port, and the second space is formed by the duct.
A heat dissipation structure characterized by: The heat dissipation structure according to claim 1 , wherein the first heat sink faces the air intake port. The heat dissipation structure according to claim 1 , wherein the second heat sink comprises a plurality of fins protruding into the duct. The heat dissipation structure according to any one of claims 1 to 4, characterized in that the volume of the second space is smaller than that of the first space. The heat dissipation structure according to any one of claims 1 to 5, characterized in that the cross-sectional diameter of the duct is smaller the farther it is from the fan.

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