Heat dissipation device for an electronic computer

Abstract

The invention relates to a heat dissipation device for an electronic computer housed in the roof of a vehicle, comprising a radial fan (204), the radial fan is housed in the thickness of the housing of the computer and is configured to circulate an air flow from the lower face of the housing towards the top of the housing via a ramp (207) positioned facing an outlet (206) of the fan. The device is characterised in that the bottom portion of the ramp (207) is truncated so as to form a spacing (208) between said ramp and the fan and so that liquid can flow from the upper portion of the housing towards the bottom, and in that a deflector (209) is positioned at the outlet of the fan so as to direct the air flow towards said ramp.

Description

Technical Field

[0001] The invention belongs to the field of thermal control of electronic devices and in particular relates to a device for cooling an electronic device intended to be incorporated into a vehicle roof. Background Art

[0002] Today, most modern vehicles are configured to receive different types of radio frequency signals. They are configured, for example, to receive FM or digital radio signals, signals transmitted by geolocation satellites, to establish a Wi-Fi connection, a Bluetooth connection, or to establish communications through a cellular access network. These communication technologies do not operate in the same frequency band and require specific configurations of antennas and demodulators.

[0003] In order to make it easier for them to be incorporated into vehicles, these communication technologies are most often incorporated into the same device, for example a TCU (Telecommunications Control Unit). The TCU may also incorporate the antennas required for receiving and transmitting radio frequency signals. This is then called a smart antenna or an intelligent antenna module (IAM). Antennas of this type are usually intended to be incorporated between the roof lining and the roof of the vehicle, these antennas protruding above the roof through apertures provided for this purpose. The antennas may be covered by a cover, for example in the form of a shark fin.

[0004] Such an antenna module incorporated into the roof is therefore exposed to high temperatures and there is a risk of water seeping in via the aperture formed in the roof through which the antenna protrudes. The module must also be compact in order to be incorporated between the headliner and the roof.

[0005] In order to meet these different requirements, a method such as Figure 1 A roof antenna module for a vehicle is depicted. The antenna module comprises a frame 101 and a cover 102, which form a housing in which a circuit board 103 and a radial fan 105 are housed. The frame 101 is configured to form a ramp 108, which is arranged opposite to a lateral outlet 110 of the fan 105 and is configured to force an air flow 109 to flow along an upper portion of the frame 101.

[0006] Figure 1 The antenna module in the embodiment is incorporated between the headliner 107 of the vehicle and the roof 100. The air guide 106 is interposed between the headliner 107 and the lower cover 102 of the antenna module so that the air penetrates the grille 108 before being guided by the guide 106 toward the inlet 111 of the fan 105 so as to generate an air flow through the lower and upper faces of the antenna module so as to cool the components 104 of the circuit board 103.

[0007] In order to protect the circuit board 103 in the event of water penetration, a seal 112 is provided. The seal 112 makes it possible to prevent liquid flowing down the slope 108 from being able to reach the circuit board 103.

[0008] This configuration is not entirely satisfactory.

[0009] Specifically, the introduction of seal 112 and its compression results in a loss of nearly 25% of the available thickness. This correspondingly reduces the rotor height of the fan. As a result, the amount of air circulated by the fan is reduced and the flow rate to noise ratio is limited (a small fan must rotate faster to provide the same flow rate).

[0010] The installation of the seal 112 requires increasing the size of the cover and introducing screws to ensure that the seal is compressed and sealed. The quality of the computer, its assembly time, its cost and its quality are all high.

[0011] Therefore, there is a need for a heat sink arrangement that does not suffer from the above-mentioned disadvantages. Summary of the invention

[0012] To this end, a heat sink device for an electronic computer is proposed, which includes a radial fan housed in the thickness of the computer's housing and configured to circulate an air flow from the lower face of the housing towards the top of the housing via a slope positioned facing the fan's outlet.

[0013] The device is characterized by:

[0014] - the bottom part of the ramp is truncated so as to create a spacing between the ramp and the fan and to allow the liquid to flow from the upper part of the housing towards the bottom, and

[0015] - A deflector is positioned at the outlet of the fan so as to direct the air flow towards said ramp.

[0016] The deflector makes it possible to introduce a gap in order to prevent water from penetrating into the compartment of the circuit, while limiting the recirculation of air between the outlet and the inlet by the spacing formed between the ramp and the fan.

[0017] This allows liquids such as rainwater to flow freely from the upper face of the housing towards the bottom of the housing without the use of seals. The absence of seals allows the use of thicker fans which can rotate slower at the same flow rate. This reduces noise. The size of the cover can also be reduced, thus limiting the mass of the computer. Finally, the assembly of the product is easier and cheaper.

[0018] According to a particular embodiment, the deflector is formed by a portion of the stator of the fan.

[0019] The deflector is thus formed in the material of the fan. This limits its weight and makes it easier to install.

[0020] According to a particular embodiment, the deflector is oriented to direct the air flow in a direction substantially parallel to the slope.

[0021] Aligning the deflector with the slope of the ramp further limits recirculation of air and improves cooling performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other aspects, objects and advantages of the invention will become apparent from the following description of one of the embodiments of the invention, which is given by way of non-limiting example. The invention will also be better understood from the accompanying drawings, in which:

[0023] Figure 1 is a cross-sectional view of an antenna module of the prior art,

[0024] Figure 2 is an exploded view of an antenna module according to a specific embodiment of the present invention,

[0025] Figure 3 is a cross-sectional view of an antenna module according to a specific embodiment,

[0026] Figure 4 is a cross-sectional view of an antenna module depicting air flow according to a specific embodiment. DETAILED DESCRIPTION

[0027] Figure 2 is an exploded view of an antenna module including a cooling device according to a specific embodiment of the invention.The antenna module is installed in the roof of a vehicle, for example between the headliner and the roof.

[0028] The antenna module comprises a housing consisting of a frame 200 and a lower cover 201 accommodating a circuit board 203 of a computer. The frame is made of, for example, metal such as aluminum or magnesium.

[0029] A radial fan 204 is housed within the thickness of the antenna module for the purpose of cooling the circuit board 203. More precisely, the fan is placed in a housing provided for this purpose in the frame 200. The fan 204 and the housing in which it is placed are configured to draw air from below the antenna module and blow it to the upper part of the frame via a lateral outlet.

[0030] Figure 2 Also shown is a roof lining 211 equipped with a grille 212 intended to allow air sucked in by the fan to circulate through the roof lining and from the vehicle's cabin towards the top of the frame 200. Finally, Figure 2An air guide 210 is shown, which is arranged between the bottom of the antenna module and the roof lining 211 and whose purpose is, on the one hand, to prevent the roof lining from being pressed against the fan due to suction and, on the other hand, to force air to circulate onto the bottom of the housing. For this purpose, the ventilation grille 212 is not placed vertically in alignment with the fan 204, but is placed below the cover 201 so that the sucked air is forced to circulate along the cover 201 before penetrating into the fan 204.

[0031] Thus, the air guide 210 interposed between the roof lining 211 and the bottom of the antenna module makes it possible to guide the air penetrating the grille 212 toward the inlet of the fan 204 so as to generate an air flow through the lower face of the antenna module so as to cool the circuit board 203 .

[0032] Figure 3 is a cross-sectional view of an antenna module according to a specific embodiment. Figure 3 More precisely shown is the portion of the antenna module in which the fan 204 is incorporated. For the sake of clarity it should be noted that like reference numerals in the Figures are used to denote like elements.

[0033] Figure 3 An inlet 205 for a fan 204 on the lower face of the antenna module is shown, as well as a lateral outlet 206 towards a ramp 207 formed by a portion of the frame 200 to direct the air flow along the upper face of the frame.

[0034] In a particular embodiment, the lower portion of the ramp 207 is truncated to form a space 208 between the outlet 206 of the fan 204 and the ramp 207. This space advantageously allows liquid flowing down the ramp 207 to flow through the grille 212 toward the bottom of the antenna module and the vehicle compartment.

[0035] In a particular embodiment, the lower end of the ramp 207 forms a lip that covers the edge surface of the cover 201 in order to prevent liquid from being able to penetrate between the frame and the cover.

[0036] In order to prevent the air exhausted by the fan from turning and being sucked through the gap 208, the device includes a deflector 209. The deflector 209 is configured to guide the air flow leaving the fan along the axis of the ramp 207 and thus limit the recirculation of a portion of the air flow through the space 208 formed for the water flow. For example, the slope of the deflector can be substantially equal to the slope of the ramp so as to minimize the angle of incidence of the air flow on the ramp. This improves the efficiency of the fan and reduces its rotation speed and / or size compared to a configuration in which the deflector is not present.

[0037] In one particular embodiment, the deflector is bonded to the stator of the fan and formed in the material of the fan, for example formed of a thermoplastic material that is lighter than the metal the frame is made of. However, according to other embodiments, the deflector is bonded to the frame and formed in the material of the frame.

[0038] Figure 4 is a cross-sectional view of an antenna module according to a particular embodiment, in which the air flows are depicted. A first primary air flow 300 circulated by the fan can be seen. The air flow 300 penetrates the fan via the lower face of the antenna module and is then directed by the deflector towards the ramp and the upper part of the housing. A recirculation loop 301 can also be seen, which is largely limited by the presence of the deflector 209.

[0039] The proposed cooling device thus enables liquid (for example, infiltrated rainwater) to flow from the top of the antenna module to the vehicle cabin without providing a seal between the cover and the frame. The space freed up by the absence of a seal makes it possible to use a fan of greater volume, thus making it possible to reduce the speed of the fan, thereby advantageously limiting noise and the energy consumed.

Claims

1. A heat sink device for an electronic computer, the heat sink device comprising a housing composed of a frame (200) and a lower cover (201), a radial fan (204) accommodated in the thickness of the housing, and a ramp (207), the ramp being formed by a portion of the frame (200) and positioned facing an outlet (206) of the fan (204), the fan (204) being configured to circulate an air flow from the lower surface of the housing toward the top of the housing via the ramp (207), the device being characterized in that: - the bottom part of the ramp is truncated so as to form a spacing (208) between the ramp and the fan (204) and to enable liquid to flow from the upper part of the housing towards the bottom, and - A deflector (209) is positioned at the outlet of the fan so as to direct the air flow towards said ramp (207).

2. An arrangement as claimed in claim 1, such that the deflector is formed by a portion of the stator of the fan.

3. A device as claimed in any one of the preceding claims, wherein: The deflector is oriented to direct the air flow in a direction substantially parallel to the ramp.

4. A roof antenna module for a vehicle, the roof antenna module comprising a cooling device as claimed in any one of the preceding claims.

5. A vehicle comprising the antenna module according to claim 4.

Images