WO2025197402A1 - Heat-dissipating structure of on-board camera - Google Patents

Abstract

A camera casing (16) of an on-board camera (15) is fixed to the cabin interior (E) side of a front window (13) and houses a CCD camera (17) and a camera controller (18) for image processing, and a slit (16a) and a connection port (16b) are formed on the rear side. An intake port (10f) and a connection port (16b) of a rear cooler unit (9) disposed between a roof (2) and a head lining (3) are connected via a duct (21), negative pressure generated in the intake port (10f) along with the operation of the rear cooler unit (9) is caused to act in the camera casing (16) via the duct (21), and the cabin interior air is introduced into the camera casing (16) via the slit (16a).

Description

Heat dissipation structure for in-vehicle cameras

The present invention relates to a heat dissipation structure for an in-vehicle camera.

In recent years, technology has been put into practical use in which an in-vehicle camera is mounted on the front window inside the vehicle, and the captured images are used to provide the driver with various information and to control the vehicle for driving assistance. However, this type of in-vehicle camera can generate heat from its built-in controller or can be exposed to direct sunlight in midsummer, raising its temperature, which can lead to malfunctions due to heat damage.

As a countermeasure, for example, the technology disclosed in Patent Document 1 provides ventilation holes at the front and rear of the camera cover, and some of the conditioned air blown out from the defroster and flowing along the windshield is introduced into the camera cover through one ventilation hole and discharged through the other ventilation hole. Furthermore, the technology disclosed in Patent Document 2 provides a heat sink with fins at the bottom of the camera housing to promote heat dissipation. Furthermore, the technology disclosed in Patent Document 3 uses a cooling fan built into the camera case to circulate air.

Japanese Patent Application Laid-Open No. 2001-88611 Patent No. 6509256 Patent No. 7115093

In the technology described in Patent Document 1, conditioned air flowing along the windshield is introduced into the camera cover through ventilation holes. Therefore, in order to introduce a sufficient amount of conditioned air, the ventilation holes on the intake side must be shaped with a large opening. Furthermore, the heat sink section described in Patent Document 2 requires a certain amount of surface area for heat dissipation, and the cooling fan described in Patent Document 3 requires a certain amount of fan diameter to ensure sufficient airflow, both of which contribute to the increase in size of the in-vehicle camera.

Furthermore, since the vehicle-mounted camera is placed near the driver's head, increasing its size causes the problem of blocking the driver's forward field of view and reducing visibility.
In addition, the operating noise emitted by the cooling fan in Patent Document 3 is perceived as noise by passengers in the front seats, and the warm air that is blown onto the passenger's face after the controller has dissipated heat can cause discomfort.

The present invention was made to solve these problems, and its purpose is to provide a heat dissipation structure for an in-vehicle camera that can efficiently dissipate heat from the controller and reliably prevent malfunctions caused by heat damage, while avoiding the reduced visibility for the driver that results from the larger size of the in-vehicle camera and the discomfort for passengers that results from operating noise and hot air.

In order to achieve the above object, the heat dissipation structure for an in-vehicle camera of the present invention is characterized by comprising: a camera casing for an in-vehicle camera that is fixed to the interior side of the vehicle's front window and that incorporates a camera unit that captures images of the area in front of the vehicle and a camera controller that processes the captured images; a communication hole that penetrates the camera casing; a connection port that is provided in the camera casing; a headlining that covers the roof of the vehicle from the inside of the passenger compartment; an air conditioning unit that is disposed between the roof and the headlining and circulates air inside the passenger compartment via an air supply and exhaust port using a blower fan between a ventilation passage formed therein and the passenger compartment; and a duct that is disposed between the roof and the headlining and connects the air supply and exhaust port of the air conditioning unit to the connection port of the camera casing.

With this heat dissipation structure for an in-vehicle camera, the air inside the vehicle is circulated by the blower fan through the intake and exhaust ports between the air conditioning unit's ventilation duct and the vehicle interior. For example, the air inside the vehicle interior may flow through the communication holes, inside the camera case, the duct, and the intake and exhaust ports in that order, or conversely, through the intake and exhaust ports, duct, inside the camera case, and the communication holes. As a result, the camera controller is exposed to the air inside the vehicle interior within the camera case, dissipating heat.

In another aspect, a pair of left and right visor mounting portions to which sun visors are attached may be formed in the front portion of the headlining, and the duct may extend in a straight line from the connection port through the space between the pair of left and right visor mounting portions to the supply and exhaust port.
Therefore, since the linear duct has low pipe resistance, the air inside the vehicle compartment flows smoothly through the duct, and the heat of the camera controller can be efficiently dissipated.

In another aspect, a pair of left and right visor mounting portions to which sun visors are attached may be formed in the front portion of the headlining, and the duct may extend from the rear side of either the left or right visor mounting portion toward the outside of the vehicle width, and further extend outside the vehicle width of the headlining to the supply and exhaust port.
Therefore, since the duct extends to the air intake and exhaust port on the outer side of the headlining in the width direction of the vehicle, head clearance is ensured and the aesthetic appearance of the headlining is improved.

In another aspect, a pair of left and right visor mounting portions to which sun visors are attached may be formed in the front portion of the headlining, and the duct may extend from the front side of either the left or right visor mounting portion toward the outside of the vehicle width, and further extend outside the vehicle width of the headlining to the supply and exhaust port.
Therefore, since the duct extends to the air intake and exhaust port on the outer side of the headlining in the width direction of the vehicle, head clearance is ensured and the aesthetic appearance of the headlining is improved.

In another aspect, a relief portion for preventing interference with the duct may be formed in a location corresponding to the rear or front side of the visor attachment portion of the headlining.
Therefore, the formation of the relief portion prevents interference between the head lining and the duct.

In another aspect, the air supply/exhaust port may be an intake port that draws in the air inside the vehicle compartment from the vehicle compartment and circulates the air through the ventilation passage.
Therefore, when the rear cooler unit is activated, negative pressure is generated at the intake port, and negative pressure also acts inside the camera casing through the duct, exposing the camera controller to the air inside the vehicle cabin that is introduced into the camera casing through the communication hole, thereby dissipating heat.

In another aspect, the air supply/exhaust port may be an outlet for blowing the air inside the vehicle compartment that has flowed through the ventilation passage into the vehicle compartment.
Therefore, a part of the air inside the vehicle compartment blown out from the air outlet is introduced into the camera casing through the duct, and the camera controller is exposed to this air inside the vehicle compartment and dissipates heat.

In another aspect, the air supply and exhaust port may be an intake port that draws in interior air from the vehicle cabin and circulates it through the ventilation passage, and an outlet port that blows the interior air that has circulated through the ventilation passage into the vehicle cabin, and the duct may be composed of a first duct that connects the intake port to the camera casing and a second duct that connects the outlet port to the camera casing.
Therefore, a portion of the air inside the vehicle cabin blown out from the outlet circulates through the second duct, the communication hole, inside the camera casing, the first duct, and the intake port in that order, and the camera controller is exposed to this air inside the vehicle cabin and dissipates heat.

In another aspect, a Venturi tube having a shape that widens toward the vehicle cabin may be disposed within the air intake port, and the rear end of the duct may be connected to a portion of the Venturi tube with a smallest diameter.
Therefore, a portion of the air in the vehicle compartment sucked into the intake port is sucked into the Venturi tube, and the pressure inside the Venturi tube decreases due to the Venturi effect, thereby increasing the negative pressure acting inside the camera casing.

The heat dissipation structure for an in-vehicle camera of the present invention prevents the driver's visibility from being reduced due to the larger size of the in-vehicle camera, as well as the discomfort to passengers caused by operating noise and hot air, while also efficiently dissipating heat from the controller, reliably preventing malfunctions caused by heat damage.

1 is a perspective view of an upper surface of a headlining provided with a heat dissipation structure for an in-vehicle camera according to a first embodiment, viewed from diagonally forward left. FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1 . 10 is a flowchart showing a forced airflow routine executed by a heat dissipation controller. FIG. 11 is a perspective view of the top surface of a headliner provided with a heat dissipation structure for an in-vehicle camera according to a second embodiment, as viewed from diagonally forward left. FIG. 6 is a partial cross-sectional perspective view showing the details of part A in FIG. 5 . FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 5 . FIG. 11 is a perspective view of the top surface of a headliner provided with a heat dissipation structure for an in-vehicle camera according to a third embodiment, as viewed from diagonally forward left. FIG. 9 is a cross-sectional view taken along line IX-IX of FIG. 8.

[First embodiment]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a heat dissipation structure for an in-vehicle camera embodying the present invention will now be described.
Fig. 1 is a perspective view of the top surface of a headlining provided with a heat dissipation structure for an in-vehicle camera, as seen from diagonally forward left, Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1, and Fig. 3 is a cross-sectional view taken along line III-III in Fig. 1. In the following description, front-rear, left-right, and up-down directions are expressed with reference to a passenger in the vehicle.

The heat dissipation structure 1 for an in-vehicle camera of this embodiment is located between the roof 2 and headlining 3 of a vehicle. The headlining 3 is an interior material that covers the roof 2 from the passenger compartment E side, and is formed with mounting portions for various components equipped in the passenger compartment E. For example, a pair of left and right visor mounting portions 5 to which sun visors 4 are fixed are formed in the front portion of the headlining 3, each of which is formed as a rectangular protrusion upward (toward the roof 2), and a rectangular lamp mounting portion 6 penetrates vertically between them. In addition, grip mounting portions 7 are formed on both the left and right sides of the headlining 3 in positions corresponding to the front seats, second-row seats, etc. When the headlining 3 is attached to the roof 2, as shown in FIG. 1, the sun visors 4 are attached to each visor mounting portion 5. Although not shown, interior lights are attached to the lamp mounting portions 6, and assist grips are attached to the grip mounting portions 7.

The approximate center of the headlining 3 in the fore-and-aft direction, specifically the area between directly above the front seats and directly above the second-row seats, bulges downward (toward the interior E of the vehicle) across the entire width of the vehicle. This defines a unit housing 8 between the headlining 3 and the roof 2, within which a rectangular box-shaped rear cooler unit 9 (corresponding to the "air conditioning unit" of the present invention) is housed and fixed. As shown in Figure 3, the headlining 3 is generally close to the roof 2 (Figure 2 shows an example of the area 19 directly above the front seats, described below), but the bottom surface 8a of the area where the unit housing 8 is defined is located lower and further away from the roof 2. However, by setting the fore-and-aft position of the unit housing 8 as described above, head clearance for occupants seated in the front seats and the second-row seats is ensured.

A ventilation passage 10 extending in the front-to-rear direction is formed within the rear cooler unit 9, and although not shown, a blower fan, a cooling evaporator, and other components are disposed within the ventilation passage 10. The front end of the ventilation passage 10 opens forward as an intake port 10f (equivalent to the "supply/exhaust port" of the present invention), and the rear end of the ventilation passage 10 opens rearward as an outlet port 10r (equivalent to the "supply/exhaust port" of the present invention). These intake port 10f and outlet port 10r are connected to the passenger compartment E via through-holes 11f, 11r, respectively, which are provided through the front and rear surfaces of the unit housing section 8.

The operating state of the rear cooler unit 9 is controlled by the air conditioning controller 12 based on the operation of an operation panel (not shown) and the vehicle interior temperature detected by a vehicle interior temperature sensor. For example, in the blower mode, the blower fan operates, and vehicle interior air is drawn in through the intake port 10f, flows through the ventilation duct 10, and then blown out into the vehicle interior E through the outlet port 10r, thereby circulating the vehicle interior air between the vehicle interior E and the ventilation duct 10. In the cooling mode, in addition to the air blown in the blower mode, refrigerant from the air conditioning system (not shown) is supplied to the evaporator to cool the vehicle interior air, thereby cooling the vehicle interior E.

Meanwhile, inside the passenger compartment E, an onboard camera 15 is fixed to the center of the upper left and right sides of the windshield 13 by a bracket (not shown). The camera casing 16 of the onboard camera 15 is shaped like a square box, and inside it houses a CCD camera 17 (corresponding to the "camera unit" of the present invention) that captures images in front of the vehicle, and a camera controller 18 that processes the images captured by the CCD camera. The processed image information is output to the vehicle's main controller (not shown), and is used, for example, to present the driver with information about road signs in front of the vehicle, or to perform vehicle control to prevent lane departure. Of course, the uses of the image information are not limited to this and can be changed as desired.

The above configuration is the same as that of a general vehicle, and next, the configuration relating to the features of this embodiment will be described.
As mentioned above, the camera controller 18 in the camera casing 16 generates heat as it executes calculations, and the temperature of the camera casing 16 rises when exposed to strong direct sunlight, especially in midsummer. This can cause the camera controller 18 to malfunction due to heat damage. To address this, the technologies disclosed in Patent Documents 1 to 3 incorporate ventilation holes, heat sinks, cooling fans, and other measures. However, these technologies have drawbacks, such as a larger in-vehicle camera 15 impairing the driver's visibility and the noise and warm air from the fan causing discomfort to front-seat passengers.

In consideration of these problems, the heat dissipation structure 1 for the vehicle-mounted camera 15 of this embodiment is designed to dissipate heat from the camera controller 18 by utilizing the air inside the vehicle cabin that is drawn into the rear cooler unit 9, and details of this structure are described below.

As mentioned above, most of the headlining 3 is close to the roof 2, and the areas 19 located directly above the left and right front seats shown in Figure 1 (hereinafter referred to as the areas directly above the front seats) are also close to the roof 2. To the rear of this area directly above the front seats 19 is formed a unit housing section 8 having a bottom surface 8a spaced further downward from the roof 2, while to the front of the area directly above the front seats 19 is formed a visor area 20 located slightly below the area directly above the front seats 19 in order to form a visor mounting section 5 that protrudes upward.

Meanwhile, as shown in Figure 2, multiple slits 16a (corresponding to "communication holes" according to the present invention) are formed on the lower rear side of the camera casing 16 of the vehicle-mounted camera 15, and these slits 16a allow communication between the interior of the camera casing 16 and the vehicle interior E. Furthermore, a connection port 16b that protrudes rearward is integrally formed on the upper rear side of the camera casing 16, and the cross-sectional shape of the connection port 16b corresponds to the cross-sectional shape of the duct 21 described below. As shown in Figure 2, the connection port 16b is located at approximately the same height as the intake port 10f of the rear cooler unit 9, and the intake port 10f and connection port 16b are connected via the duct 21 that extends in the fore-and-aft direction.

The duct 21 is linear and extends forward and backward in the side view shown in Figure 2, and as shown in Figure 1, in plan view it is also linear and extends forward and backward between the left and right visor mounting portions 5. As shown in Figure 3, the duct 21 is formed by the cooperation of a synthetic resin cover member 21a and the headlining 3. More specifically, the cross section of the cover member 21a is concave downward, and its lower edge is glued onto the headlining 3 to close it, thereby forming the cross section of the duct 21.

The front end of the duct 21 is inserted into and fixed to the connection port 16b. The duct 21 extends rearward from the connection port 16b, passing through the visor area 20 and the area 19 directly above the front seats to reach the air intake 10f, with its opening facing the air intake 10f. Because the visor area 20 is located at the same height as the lower edge of the cover member 21a, the visor area 20 closes the cover member 21a from below in its original shape. In contrast, because the area 19 directly above the front seats is located higher, a linear groove 22 extending in the fore-and-aft direction is formed on the upper surface of the area 19 directly above the front seats, and the cover member 21a is disposed within this groove 22 to form the duct 21.

When the rear cooler unit 9 operates in the ventilation mode or cooling mode, negative pressure is generated within the intake port 10f, and this negative pressure acts on the opening of the duct 21 arranged opposite the intake port 10f. As a result, negative pressure also acts within the camera casing 16 via the duct 21, and the air from within the vehicle cabin is introduced into the camera casing 16 through the slit 16a, flows through the duct 21, and then flows into the intake port 10f. This air from the vehicle cabin that flows into the intake port 10f via the duct 21 merges with the air from the vehicle cabin E that has flowed directly into the intake port 10f, and then flows through the ventilation passage 10 to the outlet port 10r.

As a result, the camera controller 18 is exposed to the air inside the vehicle cabin inside the camera casing 16. For example, when the camera controller 18 is under an excessively heavy computational load, or when it is exposed to strong direct sunlight in midsummer, the temperature of the camera controller 18 rises significantly compared to the temperature of the air inside the vehicle cabin. However, by being exposed to the air inside the vehicle cabin, heat is efficiently dissipated, and the temperature drops.

Meanwhile, the air inside the vehicle cabin used to dissipate heat from the vehicle-mounted camera 15 is controlled by a heat dissipation controller 23. A temperature sensor 24 is connected to the input side of the heat dissipation controller 23, and information relating to the temperature T inside the camera casing 16 detected by this temperature sensor 24 is input to the heat dissipation controller 23. The air conditioning controller 12 is also connected to the output side of the heat dissipation controller 23, and the air conditioning controller 12 controls the rear cooler unit 9 based on commands input from the heat dissipation controller 23, separate from the original control based on operation of the operation panel, the temperature inside the vehicle cabin, etc.

FIG. 4 is a flowchart showing a forced airflow routine executed by the heat dissipation controller 23. When the ignition switch of the vehicle is turned on, the heat dissipation controller 23 executes this routine at predetermined control intervals.
First, in step S1, it is determined whether the rear cooler unit 9 is operating. "Operating" refers to a state in which the air in the vehicle cabin is circulating through the ventilation duct 10 due to the operation of the blower fan, regardless of whether the mode is blowing air or cooling air. If the determination in step S1 is Yes (affirmative), the routine ends. If the determination is No (negative), the routine proceeds to step S2. In step S2, it is determined whether the temperature T is equal to or higher than a predetermined determination temperature T0, and if No, the routine ends. The determination temperature T0 is a threshold value set slightly lower than the upper limit temperature at which the camera controller 18 functions normally.

If step S1 is Yes, it can be assumed that the camera controller 18 continues to be exposed to the cabin air circulating inside the camera casing 16. Therefore, even if heat dissipation is required (if step S2 is Yes), if the camera controller 18 is left standing by, the camera controller 18 will gradually dissipate heat and the temperature will drop without any problems. Also, if step S2 is No, it can be assumed that heat dissipation from the camera controller 18 is not required, so there will be no problems if the camera controller is left standing by.
On the other hand, if the determination in step S2 is Yes, it is assumed that heat dissipation is required to prevent thermal damage to the camera controller 18, and the routine proceeds to step S3, where a command to force airflow is output to the air conditioning controller 12, and then the routine is terminated.

In response to this command, the air conditioning controller 12 forcibly operates the rear cooler unit 9 to blow air. The air blowing at this time may be performed in either air blowing mode or cooling mode. Because the camera controller 18 is exposed to the interior air circulating within the camera casing 16, the camera controller 18 dissipates heat and its temperature drops, reliably preventing malfunctions caused by heat damage.

Furthermore, because the rear cooler unit 9 was stopped before receiving the command, it can be assumed that the occupants do not want air conditioning. In light of this, it is desirable to select the fan mode to prevent the temperature inside the vehicle cabin from dropping excessively.

As described above, according to this embodiment, when it is determined that heat dissipation is required from the camera controller 18 based on the temperature T inside the camera casing 16, the rear cooler unit 9 is automatically activated to dissipate heat, thereby reliably preventing malfunction of the vehicle-mounted camera 15 due to heat damage.
On the other hand, according to the heat dissipation structure 1 for the vehicle-mounted camera 15 of this embodiment, the heat of the vehicle-mounted camera 15 is dissipated by utilizing the air inside the vehicle cabin that is sucked into the rear cooler unit 9, thereby solving the problems encountered in Patent Documents 1 to 3.

First, the camera casing 16 can be prevented from becoming larger. More specifically, the camera casing 16 of this embodiment does not have the ventilation holes on the inlet side of Patent Document 1, which would increase the size. Furthermore, the camera casing 16 does not have any built-in components equivalent to the heat sink portion of Patent Document 2 or the cooling fan of Patent Document 3, which would also increase the size.

In this embodiment, in order to apply the negative pressure generated at the intake port 10f of the rear cooler unit 9 to the inside of the camera casing 16, it is necessary to form a connection port 16b in the camera casing 16 for inserting and fixing the front end of the duct 21. However, because the connection port 16b is a very small part, it does not increase the size of the camera casing 16, nor does it increase the size of the slit 16a that introduces air into the vehicle cabin. Therefore, the onboard camera 15 can be positioned without obstructing the driver's forward view, thereby achieving good visibility.

Furthermore, because the camera casing 16 does not have a built-in cooling fan, no operating noise is generated, and although air from the vehicle interior is drawn into the camera casing 16 through the slits 16a, no warm air is blown out after the camera controller 18 has dissipated its heat. This prevents the discomfort felt by passengers due to these operating noises and warm air.

In addition, because the duct 21 is formed in a straight line extending back and forth between the left and right visor mounting portions 5 in a plan view, there are no bends and the pipe resistance is low. This allows the air inside the vehicle cabin to flow smoothly toward the intake port 10f via the duct 21, and also achieves the effect of applying sufficient negative pressure inside the camera casing 16 to efficiently dissipate heat from the camera controller 18.

However, vehicles are often destined for a wide variety of destinations, some of which require the heat dissipation structure 1 of this embodiment, and some of which do not. Equipping vehicles for all destinations with the heat dissipation structure 1 would result in unnecessary cost increases for vehicles destined for destinations where the heat dissipation structure 1 is not required, and producing vehicles with and without the heat dissipation structure 1 depending on the destination would also result in cost increases.

On the other hand, situations requiring heat dissipation from the camera controller 18 occur frequently in environments where the outside air temperature is high and the vehicle is exposed to strong direct sunlight, such as hot regions, but do not occur in cold regions. Furthermore, vehicles for hot regions often already have a rear cooler unit 9 or a circulator unit (with only a blowing function) installed in the roof 2 at the request of the customer. Therefore, using such existing vehicles as a base, vehicles can easily be equipped with the heat dissipation structure 1 by simply making minor specification changes, such as adding a duct 21 or modifying the shape of the headlining 3 and camera casing 16. On the other hand, vehicles for cold regions do not have a rear cooler unit 9 or the like, but because the heat dissipation structure 1 is not originally required, there is no need to add such a structure. As a result, unnecessary additional equipment such as a rear cooler unit 9 can be prevented, and the heat dissipation structure 1 for the camera controller 18 can be equipped in the vehicle with minimal specification changes as needed.

Second Embodiment
Next, a second embodiment of the heat dissipation structure 1 for an in-vehicle camera 15 embodying the present invention will be described.
Figure 5 is a perspective view of the top surface of the headlining 3 on which the heat dissipation structure 1 for the vehicle-mounted camera 15 is provided, viewed from diagonally forward left, Figure 6 is a partial cross-sectional perspective view showing details of part A in Figure 5, and Figure 7 is a cross-sectional view taken along line VII-VII in Figure 5.

The differences from the first embodiment are that the configuration and routing of the duct 31 have been changed, and that the negative pressure generated in the Venturi tube is applied to the inside of the camera casing 16 via the duct 31. Therefore, the same component numbers will be used for common configuration parts, and explanations will be omitted, with the focus being on the differences.

In this embodiment, the duct 31 is manufactured as an independent synthetic resin pipe material separate from the headlining 3. The duct 31 is fixed to the underside of the roof 2 by multiple pipe holders 32 spaced apart in the longitudinal direction. As shown in an example in Figure 7, the pipe holder 32 is made of a plate-shaped base portion 32a and an annular holder portion 32b with a notch, which are integrally formed from a synthetic resin material. The base portion 32a of each pipe holder 32 is fixed to a predetermined position on the underside of the roof 2, and the duct 31 is fitted into the holder portion 32b via the notch, thereby fixing the duct 31 to the roof 2 along a predetermined path.

The connection port 16b of the camera casing 16 has a circular cross section that corresponds to the cross section of the duct 31, and the front end of the duct 31 is inserted and fixed into it. The duct 31 extends rearward from the connection port 16b, then bends left at a right angle, extending leftward (corresponding to the "outside of the vehicle width" in this invention) behind the left visor mounting portion 5. The duct 31 further bends rearward at a right angle, extending rearward on the left side of the area 19 directly above the front seats (corresponding to the "outside of the vehicle width" in this invention), then bends right at a right angle, with its rear end inserted into the intake port 10f of the rear cooler unit 9.

As shown in Figure 7, a recess 33 with a semicircular cross section that bulges downward is formed in the visor region 20 at a location corresponding to the rear of the visor mounting portion 5, thereby preventing interference with the duct 31.

The routing path of the duct 31 may be changed to be symmetrical, with the rear side of the right visor mounting portion 5 extending to the right (corresponding to the "outside of the vehicle width" in this invention), and the right side of the area 19 directly above the front seat (corresponding to the "outside of the vehicle width" in this invention) extending rearward.

A Venturi tube 34 is disposed within the intake port 10f. The Venturi tube 34 is cylindrical and widens toward the front; more specifically, it has a maximum inner diameter on the passenger compartment E side and gradually decreases in diameter toward the ventilation passage 10 side. The rear end of the duct 31 inserted into the intake port 10f is connected to the smallest diameter part of the Venturi tube 34.

When the rear cooler unit 9's blower fan is activated, air inside the vehicle cabin is sucked into the intake port 10f, and some of it is sucked into the Venturi tube 34. Within the Venturi tube 34, the Venturi effect causes the passage cross-sectional area to decrease, increasing the flow rate of the air inside the vehicle cabin, resulting in a corresponding drop in pressure. As a result, negative pressure is generated within the intake port 10f within the Venturi tube 34; in other words, a negative pressure higher than that of the first embodiment. This negative pressure then acts on the camera casing 16 via the duct 31, just as in the first embodiment, and, although this will not be explained again, this allows heat to be dissipated from the camera controller 18.

Although the Venturi tube 34 is installed in the intake port 10f, the interior air that flows through the Venturi tube 34 flows into the ventilation passage 10 together with the interior air that is directly drawn into the intake port 10f. This allows for a higher negative pressure to be generated without reducing the air-blowing capacity or cooling capacity of the rear cooler unit 9.

In the first embodiment, the duct 21 took a path that crossed the area 19 directly above the front seats from front to back, which required the formation of a deep groove 22 in the area 19 directly above the front seats to accommodate the duct 21. This groove 22 protruded toward the interior E of the vehicle, reducing head clearance and detracting from the aesthetic appeal of the headlining 3. In contrast, the duct 31 in this embodiment extends rearward on the left side of the area 19 directly above the front seats, allowing the original shape of the area 19 directly above the front seats without the groove 22 to be maintained, resulting in the benefits of ensuring head clearance and improving the aesthetic appeal of the headlining 3.

While this has advantages, the path of duct 31 becomes more complex, and the increased number of bends increases pipe resistance. Negative pressure within the camera casing 16 is generated by circulating the air from the vehicle cabin toward the intake port 10f via duct 31. Therefore, when pipe resistance increases, there is insufficient negative pressure acting within the camera casing 16, and this insufficient negative pressure leads to an insufficient amount of air from the vehicle cabin being introduced into the camera controller 18 through the slits 16a, which in turn leads to insufficient heat dissipation from the camera controller 18.

To address this issue, in this embodiment, the negative pressure is increased by using a Venturi tube 34. This allows a high negative pressure comparable to that in the first embodiment to be applied inside the camera casing 16, thereby enabling the camera controller 18 to efficiently dissipate heat.
However, depending on the cross-sectional area and length of the duct 31, it may be possible to apply a sufficient negative pressure to the inside of the camera casing 16 without providing the Venturi tube 34. In such cases, the Venturi tube 34 may be omitted.

[Third embodiment]
Next, a third embodiment of the heat dissipation structure 1 for an in-vehicle camera 15 embodying the present invention will be described.
Fig. 8 is a perspective view of the top surface of the headlining 3 provided with the heat dissipation structure 1 for the vehicle-mounted camera 15 of the third embodiment, as seen from diagonally forward left, and Fig. 9 is a cross-sectional view taken along line IX-IX in Fig. 8. Note that Fig. 6, which was used to explain the second embodiment, is also common to this embodiment.

The difference from the second embodiment is that the routing path of the duct 41 has been changed. For example, the Venturi tube 34 and other components are common, so the same component numbers are used for common components, and explanations will be omitted, with the focus being on the differences.

8 and 9, the duct 41 in this embodiment extends in the left-right direction in front of the left visor mounting portion 5. More specifically, the duct 41 extends rearward from the connection port 16b, then bends left at a right angle and extends leftward (corresponding to the "outside of the vehicle width" in this invention) from the front side of the left visor mounting portion 5. The duct 41 then bends rearward at a right angle and extends rearward from the left side of the area 19 directly above the front seats (corresponding to the "outside of the vehicle width" in this invention), then bends right at a right angle and its rear end is inserted into the intake port 10f of the rear cooler unit 9. Naturally, a recess 42 to prevent interference with the duct 41 is formed in the visor area 20 at a location corresponding to the front side of the visor mounting portion 5.

In the second embodiment, the recess 33 is located behind the visor mounting portion 5, in other words, in a position close to the occupant's head, as shown in Figures 5 and 7, which may cause a slight feeling of oppression to the occupant and also leaves room for improvement in terms of aesthetics. In contrast, in this embodiment, the recess 42 is formed in a position further away from the occupant's head, which reduces the feeling of oppression and, because the recess 42 appears as a sun visor 4 when viewed from the occupant's side, prevents a loss of aesthetic appeal.

This concludes the description of the embodiment, but the aspects of the present invention are not limited to this embodiment. For example, in the above embodiment, the camera controller 18 was dissipated heat using the negative pressure generated at the intake port 10f of the rear cooler unit 9, but this is not limited to the rear cooler unit 9, and the negative pressure of the circulator described above may also be used. Since this is common to the rear cooler unit 9, a duplicated explanation will not be given, but the structure is such that the negative pressure generated at the intake port of the circulator is applied to the inside of the camera casing 16 via a duct.

In addition, in the above embodiment, negative pressure was applied inside the camera casing 16 by connecting the connection port 16b of the camera casing 16 to the intake port 10f of the cooler unit via ducts 21, 31, and 41, but this is not limited to this. For example, the connection port 16b of the camera casing 16 may be connected to the outlet port 10r of the rear cooler unit 9 via a duct. In this case, some of the air inside the vehicle compartment blown out from the outlet port 10r is introduced into the camera casing 16 via the duct, and then discharged into the vehicle compartment E through the slit 16a. As a result, the camera controller 18 is exposed to the air inside the vehicle compartment and dissipates heat, as in the above embodiment, thereby achieving the various effects described above.

Furthermore, as in the above embodiment, the connection port 16b of the camera casing 16 may be connected to the intake port 10f of the rear cooler unit 9 via ducts 21, 31, and 41 (corresponding to the "first duct" of the present invention), and the slit 16a of the camera casing 16 may be connected to the outlet port 10r of the rear cooler unit 9 via another duct (corresponding to the "second duct" of the present invention). In this case, a portion of the air inside the vehicle cabin blown out from the outlet port 10r of the rear cooler unit 9 circulates through the other duct, the slit 16a, inside the camera casing 16, ducts 21, 31, and 41, and then the intake port 10f, thereby dissipating heat from the camera controller 18 within the camera casing 16. In this case, the same various effects as in the above embodiment can be achieved.

1 Heat dissipation structure 2 Roof 3 Headlining 4 Sun visor 5 Visor mounting portion 9 Rear cooler unit (air conditioning unit)
10 Ventilation path 10a Intake port (intake/exhaust port)
10b Air outlet (intake/exhaust port)
13 Front window 15 In-vehicle camera 16 Camera casing 16a Slit (communication hole)
16b Connection port 17 CCD camera (camera unit)
18 Camera controller 21, 31, 41 Duct (first duct)
33, 42 Relief portion 34 Venturi tube

Claims (9)

a camera casing for an in-vehicle camera that is fixed to the interior side of a front window of a vehicle and that incorporates a camera unit that captures an image of the area in front of the vehicle and a camera controller that processes the captured image;
a communication hole formed through the camera casing;
a connection port provided in the camera casing;
a headlining that covers the roof of the vehicle from the inside of the vehicle compartment;
an air conditioning unit disposed between the roof and the head lining, the air conditioning unit circulating air in the vehicle interior by a blower fan through an air intake and exhaust port between an air passage formed therein and the vehicle interior;
a duct disposed between the roof and the head lining, the duct connecting the air supply/exhaust port of the air conditioning unit and the connection port of the camera casing;
A heat dissipation structure for an in-vehicle camera, comprising: A pair of left and right visor mounting portions to which sun visors are attached are formed in the front portion of the headlining,
2. The heat dissipation structure for an in-vehicle camera according to claim 1, wherein the duct extends linearly from the connection port to the supply/discharge port through a gap between the pair of left and right visor mounting portions. A pair of left and right visor mounting portions to which sun visors are attached are formed in the front portion of the headlining,
The heat dissipation structure for an in-vehicle camera described in claim 1, characterized in that the duct extends toward the outside of the vehicle width from the rear side of either the left or right visor mounting portion, and further extends toward the outside of the vehicle width of the headlining to the intake and exhaust port. A pair of left and right visor mounting portions to which sun visors are attached are formed in the front portion of the headlining,
The heat dissipation structure for an in-vehicle camera described in claim 1, characterized in that the duct extends toward the outside of the vehicle width from the front side of either the left or right visor mounting portion, and further extends toward the outside of the vehicle width of the headlining to the intake and exhaust port. 5. The heat dissipation structure for an in-vehicle camera according to claim 3, wherein a recess is formed in a location corresponding to the rear or front side of the visor mounting portion of the headlining to prevent interference with the duct. 2. The heat dissipation structure for an in-vehicle camera according to claim 1, wherein the air intake/exhaust port is an intake port that draws air from the vehicle interior and circulates it through the ventilation passage. 2. The heat dissipation structure for an in-vehicle camera according to claim 1, wherein the intake/exhaust port is an outlet port for blowing the air circulating through the ventilation passage into the vehicle interior. the air supply/exhaust port is an intake port that draws in the interior air from within the vehicle interior and circulates it through the ventilation passage, and an outlet port that blows the interior air that has circulated through the ventilation passage into the vehicle interior,
2. The heat dissipation structure for an in-vehicle camera according to claim 1, wherein the duct comprises a first duct connecting the inlet and the camera casing, and a second duct connecting the outlet and the camera casing. A Venturi tube having a shape that widens toward the interior of the vehicle cabin is disposed within the intake port,
7. The heat dissipation structure for an in-vehicle camera according to claim 6, wherein a rear end of the duct is connected to a portion of the Venturi tube having a minimum diameter.