JP4002425B2 - Housing structure of audio equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a housing structure of an on-vehicle audio device incorporating a disc player, and in particular, the heat generated by an electronic component having a large calorific value such as a power IC adversely affects the pickup portion of the disc player. It relates to heat dissipation measures to avoid receiving.
[0002]
[Prior art]
In an in-vehicle audio device incorporating a disc player such as a CD player, an MD player, or a DVD player, a heat generating element with high power consumption such as a power IC that supplies power to the disc player is required. Appropriate heat dissipation measures must be taken so that the temperature inside the housing does not rise excessively due to heat released from the element. This is because if the internal temperature of the housing becomes too high due to the heat generated by a heat source such as a power IC, the risk of adversely affecting the performance and reliability of various electronic components arranged in the housing increases. It is.
[0003]
Conventionally, a housing structure as shown in FIGS. 4 and 5 has been widely adopted as a heat dissipation measure for such in-vehicle acoustic devices. Here, FIG. 4 is a schematic configuration diagram of an audio device according to a conventional example, and FIG. 5 is an explanatory diagram of airflow in a housing of the audio device. In these drawings, a disc player 3 and a circuit board 4 are vertically arranged in a casing indicated by a reference numeral 5 so as to be spaced apart from each other by a predetermined amount. A power IC 1 for supplying power to is mounted. Since the power IC 1 is a heat source that generates a large amount of heat during use, the power IC 1 is attached to a heat sink (heat radiating member) 2 formed of a metal material having excellent thermal conductivity such as aluminum. In addition, an upper vent 6 and a lower vent 7 facing the space in the vicinity of the power IC 1 are respectively provided in the top plate and the bottom plate of the housing 5, and a circuit is provided between the vents 6 and 7. A substrate vent 8 is also provided in the substrate 4. These vent holes 6 to 8 are for forming an air flow from below to above in the vicinity of the power IC 1 and the heat sink 2.
[0004]
More specifically, the heat generated by the power IC 1 is conducted to the heat sink 2 and radiated to the space around the power IC 1 itself, so that the air in the vicinity of the power IC 1 and the heat sink 2 is heated and rises. Since this updraft is discharged to the outside through the upper vent 6 of the casing 5 that is opened directly above, the outside air is discharged from the lower vent 7 of the casing 5 that is opened immediately below by the negative pressure. As a result, an air flow as shown by an arrow in FIG. 5 is formed on one side of the housing 5. That is, when the power IC 1 generates heat, the air flowing in from the lower vent 7 passes through the substrate vent 8 and then rises while being heated along the power IC 1 and the heat sink 2, and this updraft passes through the upper vent 6. Then, it is discharged upward of the housing 5. In this way, the power IC 1 is installed on one side of the housing 5, and the air flow from the lower side to the upper side is formed between the upper vent 6 and the lower vent 7 of the housing 5 while using the heat sink 2 together. If formed, the heat generated by the power IC 1 is less likely to fill the interior of the housing 5, so that the temperature inside the housing 5 can be prevented from rising excessively.
[0005]
[Problems to be solved by the invention]
In the conventional heat dissipation measures described above, an air flow from the lower side to the upper side is formed on one side of the housing 5, so that the air in the disc player 3 is not easily heated by the power IC 1 or the heat sink 2. However, since a significant air flow is not formed elsewhere in the housing 5, it is not possible to expect a sufficient heat dissipation effect against the temperature rise in the disc player 3. That is, FIG. 6 is a schematic diagram showing the temperature distribution during power IC heat generation in the housing shown in FIGS. 4 and 5, and a particularly high temperature region H1 is widened in the vicinity of the power IC 1 and the heat sink 2 in the housing 5. In addition, it can be seen that a slightly high temperature region H2 extends inside the disc player 3. Note that a region H3 in FIG. 6 is a region that is cooler than the region H2 but hotter than the outside air.
[0006]
If the temperature in the disc player 3 rises undesirably in this way, the life of the semiconductor laser incorporated in the pickup section of the disc player 3 is greatly shortened, or the recording medium is heated as heat. When a weak CD-R is used, there is a problem that information recorded on the CD-R is lost.
[0007]
In addition, instead of performing heat dissipation by such natural convection, a method of attaching a cooling fan to perform forced ventilation is also conceivable, but if a fan is attached to the housing 5, it will be forced to increase cost and size, In addition, forced ventilation with fans is generally used in in-vehicle audio equipment because the dust-proof property is impaired and the reliability of the pickup unit is reduced, and the wind noise of the fan becomes noise that impairs the sound quality. I have not been told. Moreover, in order to enhance the heat dissipation effect by natural convection, a method of providing a large number of ventilation holes and large openings in the housing 5 is also conceivable, but this is not preferable from the viewpoint of dust resistance.
[0008]
The present invention has been made in view of the situation of the prior art, and an object of the present invention is to provide a housing structure for an acoustic device that can effectively suppress a temperature rise in a disc player by heat dissipation by natural convection. It is in.
[0009]
[Means for Solving the Problems]
The present invention is provided on the other side of the casing, separately from the upper and lower vents that form an air flow upward from below in the vicinity of a heat source such as a power IC at one side in the casing. In addition , a circuit board located between the upper and lower vents is opened on the circuit board located between the upper and lower vents. The outside air taken in from the vents was pulled by the air flow and moved in the housing. Accordingly, since the outside air taken in from the side vents can be directed to the air flow while moving along the disc player, heat exchange with the air in the vicinity of the disc player can be promoted.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
In the housing structure of an audio device according to the present invention, a disc player having a pickup unit is housed and held inside the housing, and a heat generating element is attached to a heat sink disposed on one side of the housing. In addition, an upper vent and a lower vent are formed in the top plate portion and the bottom plate portion of the housing, respectively, for forming an air flow from the lower side to the upper side facing the space in the vicinity of the heating element. A side vent for taking in outside air from the other side of the housing toward the airflow is a part of the housing that protrudes to the other side (for example, of the housing). A circuit board that is located on the side plate portion at a location facing the heat generating element) and is located on the same line as the upper vent and the lower vent on the circuit board disposed between the upper vent and the lower vent and that the vents are opened It was.
[0011]
In such a case structure, heat is supplied from the heat generating element such as a power IC or heat sink to the nearby air at one side of the case, and the upper vent is passed from the lower vent through the substrate vent. In addition to forming an air flow (updraft) toward the air, the air existing between the updraft and the side vents provided on the other side of the housing is pulled by the updraft, Since the air flow that moves sideways is formed, the latter air flow can be moved along the disc player to absorb the heat of the disc player by the low-temperature outside air taken in from the side vents. it can. In addition, since the circuit board has a board vent located on the same line as the upper vent and the lower vent, an air flow is formed in a straight line from the lower vent through the board vent to the upper vent. It is preferable.
[0012]
In the above configuration, when the disc player is stored and held above the space interposed between the side vent and the heat generating element in the housing and the circuit board is stored and held below the space, the side vent is provided. Therefore, there is no possibility that dust will fall into the disc player with the flow of outside air from the heater to the heat generating element, which is preferable for maintaining the dustproof property in the disc player .
[0013]
【Example】
An embodiment will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of an audio device according to this embodiment, FIG. 2 is an explanatory diagram of airflow in the housing of the audio device, and FIG. 3 is a power IC in the housing. It is a schematic diagram which shows the temperature distribution at the time of heat_generation | fever, and the same code | symbol is attached | subjected to the part corresponding to FIGS.
[0014]
The audio equipment shown in FIGS. 1 and 2 is an on-vehicle audio equipment in which a casing 5 is installed in a vehicle interior, and a disc player 3, a circuit board 4, a power IC 1, a heat sink 2, and the like are arranged inside the casing 5. Has been. An upper vent 6 and a lower vent 7 are respectively formed in the top plate portion and the bottom plate portion of the housing 5, and the side vent 9 is provided in the side plate portion of the housing 5 on the side where the power IC 1 does not exist. Is different from the conventional example described above in that the side vent 9 is added. The front surface (front surface in FIG. 1) of the housing 5 is formed by a panel called a nose, and a disc is inserted into the disc player 3 from an insertion port (not shown) provided in this panel. Is inserted, and the disc is ejected from the disc player 3.
[0015]
That is, also in this embodiment, the disc player 3 and the circuit board 4 are vertically arranged in the casing 5 with a predetermined distance therebetween, and power is supplied to the disc player 3 at one end on the circuit board 4. A power IC 1 is mounted. Since the power IC 1 is a heating element that generates a large amount of heat during use, the power IC 1 is attached to a heat sink (heat radiating member) 2 formed of a metal material having excellent thermal conductivity such as aluminum. Further, the upper vent 6 opened in the top plate portion of the housing 5 and the lower vent 7 opened in the bottom plate portion are both opposed to the space between the heat sink 2 and the disc player 3 in the vicinity of the power IC 1. The circuit board 4 is also provided with a board vent 8 between the vents 6 and 7. These vent holes 6 to 8 are for forming an air flow (upward air flow) from the lower side to the upper side in the vicinity of the power IC 1 and the heat sink 2. However, in the case where the circuit board 4 does not exist between the upper and lower vents 6 and 7, the board vent 8 is not necessary. On the other hand, the side air vent 9 opened at a position substantially opposite to the power IC 1 on the side plate portion of the housing 5 on the side opposite to the heat sink 2 is for taking in outside air that passes through the side plate portion and goes to the rising airflow. The outside air taken in from the side vents 9 can be merged with the rising airflow while moving along the bottom surface of the disc player 3.
[0016]
In the present embodiment having such a housing structure, the heat is supplied from the power IC 1 or the heat sink 2 to the nearby air at one side in the housing 5, and then travels from the lower vent 7 to the upper vent 6. Not only is an ascending airflow (upward arrow in FIG. 2) formed, but air existing between this ascending airflow and the side vent 9 provided on the other side of the housing 5 becomes the ascending airflow. By being pulled, an air flow (a left-pointing arrow in FIG. 2) that moves sideways in the housing 5 is formed. The latter air flow is an air flow in which the low-temperature outside air taken in from the side vent 9 moves along the bottom surface of the disc player 3, so that the air flow absorbs heat in the disc player 3. can do. When the temperature distribution during energization in the housing 5 is actually examined, as shown in FIG. 3, the slightly high temperature region H2 hardly spreads inside the disc player 3, and the conventional example (see FIG. 6). It can be seen that the temperature in the disc player 3 is kept lower than that in FIG. Further, from the temperature distribution shown in FIG. 3, the particularly high temperature region H1 in the vicinity of the power IC 1 and the heat sink 2 is narrowed, and the temperature in the lower region of the disc player 3 is kept almost as low as the outside air. I understand. In addition, the area | region H3 in FIG. 3 has shown the area | region where it is colder than the area | region H2, but compared with external air.
[0017]
Further, in this embodiment, even if some dust is mixed in the outside air taken into the housing 5 from the side vent 9, the outside air passes below the disc player 3 and becomes the upward air flow. Therefore, there is no fear that dust will fall into the disc player 3. Therefore, according to the present embodiment, it is possible to effectively suppress the temperature rise in the disc player 3 by heat radiation by natural convection without using a cooling fan that is concerned about cost increase, size increase, noise, and the like. Therefore, it is easy to maintain the reliability of the pick-up part etc., where the upper limit temperature during use is severe.
[0018]
Note that a structure may be provided in which the dust-proof property in the housing 5 is enhanced by providing a filter in the side vent 9. Further, when dust-proof measures are taken, there is no problem even if the air flow that flows in from the side vent 9 and goes to the ascending air current passes above the disc player 3. The vertical positional relationship between the disc player 3 and the circuit board 4 may be reversed, and the side vents 9 may be opened at the top of the housing 5. Further, when dust prevention measures are taken and there is a margin in cost and size, it is possible to further improve the heat dissipation effect by using a cooling fan in combination.
[0019]
Further, in the present embodiment, the case where the side vents 9 are provided in the side plate portion of the housing 5 on the side opposite to the heat sink 2 has been described, but the corner portion of the top plate portion of the housing 5 adjacent to the side plate portion. Alternatively, similar side vents may be provided at the corners of the bottom plate. Further, the heat sink 2 is not necessarily arranged inside the housing 5, and may be a structure that is exposed on one side of the housing 5 and that the heat sink 2 itself also serves as a side surface of the housing 5.
[0020]
【The invention's effect】
The present invention is implemented in the form as described above, and has the following effects.
[0021]
Heat that flows from the lower vent to the upper vent through the board vent is formed by heat supplied to the nearby air from a heat generating element such as a power IC or a heat sink on one side of the housing (updraft) In addition, the air existing between the updraft and the side vents provided on the other side of the casing is pulled by the updraft, and an airflow that moves sideways in the casing is formed. Therefore, by moving the latter air flow along the disc player, the heat inside the disc player can be absorbed by the low temperature outside air taken in from the side vents, and therefore, heat dissipation by natural convection can be achieved. The temperature rise in the disc player can be effectively suppressed. In addition, since the circuit board has a board vent located on the same line as the upper vent and the lower vent, an air flow is formed in a straight line from the lower vent through the board vent to the upper vent. It is preferable.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an audio device according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram of air flow in a housing of the acoustic device.
FIG. 3 is a schematic diagram showing a temperature distribution during use in the housing.
FIG. 4 is a schematic configuration diagram of an audio device according to a conventional example.
FIG. 5 is an explanatory diagram of air flow in the housing of the acoustic device.
FIG. 6 is a schematic diagram showing a temperature distribution during use in the housing.
[Explanation of symbols]
1 Power IC (heating element)
2 Heat sink 3 Disc player 4 Circuit board 5 Housing 6 Upper vent 7 Lower vent 8 Substrate vent 9 Side vent

Claims (3)

With disc player having a pickup portion in the interior of the housing is accommodated and held, the heating elements to the heat sink which is disposed on one side of the housing is attached, and the top plate portion of the housing In the acoustic device in which an upper vent and a lower vent for forming an air flow from the lower side to the upper side facing the space in the vicinity of the heat generating element are formed in the bottom plate portion and the bottom plate portion, respectively.
A side vent for taking in outside air from the other side of the housing to the air flow is opened in a portion of the housing that protrudes to the other side ,
A circuit board disposed between the upper vent and the lower vent is provided with a board vent located on the same line as the upper vent and the lower vent . Enclosure structure.   2. The housing structure of an acoustic device according to claim 1, wherein the side vent is opened at a position facing the heat generating element in a side plate portion on the other side of the housing.   3. The disk player according to claim 2, wherein the disc player is stored and held above a space interposed between the side vent and the heat generating element in the casing, and a circuit board is stored and held below the space. A housing structure of an acoustic device characterized by the above.

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