JPS60252040A - Car-mounting acoustic apparatus - Google Patents

Abstract

PURPOSE:To reduce thermal capacity as well as to improve radiant effeciency, by making up a box body part excepting at least operating and displaying parts into a double constitution of a thin plate forming the outer wall and a frame having a surface area being less than another thin plate installed inside the thin plate. CONSTITUTION:A base plate 2 or the like mounted with electronic part, etc., is locked to a body chassis 1. In addition, an operation-display pannel 8 and both upper and lower covers 3 are coupled with the body chassis 1 by means of screws 4. In this case, these upper and lower cover 3 are formed into a double construction consisting of an outer plate 6 serving as a thin plate forming each outer wall and reinforced frame 7 having a surface area being less than the said plate 6 installed in the inside. And, a thin film 9 being high in a reflecting factor, to a hot wire or a ray of light, than a blank of the said plate 6 is formed on an outer surface of the outer plate 6 by means of a proper method. With this constitution, such a box body as well as being small in thermal capacity and speedy in radiation of heat is securable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to in-vehicle audio equipment, and particularly to one that solves the heat problem therein.

[Prior art]

Generally, the interior of a vehicle, where in-vehicle audio equipment is placed, is in a harsh environment, with temperatures reaching over 80 degrees Celsius and continuous exposure to direct sunlight. By the way, to deal with such high temperatures, in addition to ensuring the heat resistance of each component and the materials used, in order to reduce the temperature rise inside the case, we have taken measures such as reducing power consumption, installing heat sinks for heat generating parts, and installing ventilation holes. is being carried out.

In addition to ensuring the heat resistance of the material against direct sunlight, countermeasures such as plating, painting, printing, and adhesion are selected to ensure strength.

However, the problems and countermeasures cited here mainly concern the reliability of the equipment itself and the steady environment, and have been thoroughly studied in the past.

On the other hand, there are other 8Rs of heat in in-vehicle audio equipment. For example, there is a problem in that the cassette player absorbs heat from other adjacent heat generating devices 2, such as power amplifiers, and the built-in cassette bag becomes too warm for the operator to touch.

This is an in-vehicle compact disc player (CD
The situation is similar to the temperature rise of the disc in a player (referred to as a player).

In CD players, there is a further heat problem of a different nature. So-called compact discs use light to read information recorded as irregularities on the disc, and a laser light source is used as the light source so that the spot diameter of the light can be narrowed down to an extremely small size. The optimum wavelength for this light source is 7BOn2 m (10 m), and this wavelength was already achievable with semiconductor laser diodes (hereinafter referred to as laser diodes) at the time the compact disc standard was decided, and was also announced by each manufacturer. Laser diodes are used in most of the products.

Laser diodes have the advantage of being extremely compact and low power consumption compared to other laser light sources, but at present they are not suitable for use in automobiles due to their reliability in continuous high-temperature operation, or in other words, their longevity. It cannot be said that it is sufficient for the purpose. That is, if a laser diode is left on for a long time in a vehicle interior that is left under conditions of high temperature and strong direct sunlight, the failure rate of the laser diode will significantly increase.

On the other hand, if the CD player operates only when there is a listener in the vehicle, the upper limit of the temperature of the interior of the vehicle will naturally be lower, and the upper limit of the steady temperature will be lower. The temperature is approximately 40℃,
At this temperature, the laser diode also has almost the desired reliability.

However, even if this idea is possible on a regular basis, a CD player heated to a high temperature may open a car window,
When starting the cooler or opening the windows, a high temperature condition still exists during the transition period when the temperature gradually drops as the vehicle is driven. In general, the temperature of the air inside a vehicle decreases with a thermal time constant of several minutes simply by opening the windows and doors, whereas the structure inside a CD player, especially around the laser diode, has an extremely large thermal time constant. , is often about several tens of minutes. (1) The laser diode is fixed and positioned with extremely high positional accuracy along with other optical components;
For this mounting base, metal such as aluminum die-casting having a large wall thickness is used for its dimensional stability and ease of processing, and therefore the structure including the laser diode has a large heat capacity (large heat capacity).

(2) Since the optical system including the laser diode is configured to move in the radial direction of the compact disk,
Heat conduction between this movable part and a non-movable part such as a CD player housing is poor (the heat conduction path is narrow).

(3) Since the optical system including the laser diode does not like the intrusion of dust, it is not possible to provide a very large ventilation hole in the CD player case (heat dissipation by air convection is inefficient).

This is due to the following reasons.

From the perspective of protecting the laser diode, it is necessary to prevent the laser diode from turning on until the temperature of the laser diode has sufficiently decreased, for example by installing a temperature sensor. It is inconvenient, and even though the air temperature inside the vehicle has dropped sufficiently, C.
It can be said that it is inexplicable that the D player is inoperable.

Also, the ambient temperature of the laser diode, in other words, the CD
In keeping the humidity and temperature of the player housing low, as mentioned above, the influence of heat generated by adjacent heat generating elements, especially the same vehicle-mounted audio equipment, is also significant.

When considering the above-mentioned problem of the heat dissipation time constant of in-vehicle audio equipment or heat absorption from other sets with respect to the housing structure of conventional in-vehicle audio equipment, the following situation arises.

First, conventional casings generally have a strong structure made of iron sheet metal for the purpose of ensuring mounting strength and shielding against various electromagnetic interferences, and have a relatively large heat capacity. For this reason, for sets that generate a lot of heat, a heat sink or the like is dedicated to the heat generating part and exposed outside the casing, but other casing surfaces also generate heat, which warms other units placed adjacent to it. In addition, while general casings may be devised to increase the heat resistance of the casing surface in order to have some effect on heat generation, the reverse is not the case.
This has caused problems such as the fact that other heat generation components are easily absorbed, and the degree of temperature rise due to direct sunlight irradiation is increased.

[Summary of the invention]

The present invention was made in view of the problems of the conventional products as described above, and the outer wall of the casing is made of a thin plate with insufficient strength but low heat capacity, and the minimum surface area necessary to ensure strength. By combining a frame with By forming a thin film through coloring or chemical treatment, it is possible to reduce heat generation and heat absorption from that surface, and the purpose is to provide in-vehicle audio equipment that can reduce the impact on other sets. .

[Embodiments of the invention]

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an in-vehicle audio device having a double-structured housing according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a main body chassis, to which a board 2 and the like on which electronic components and the like are mounted are fixed. Reference numeral 8 denotes an operation/display panel as an operation/display section, and 3 indicates upper and lower covers, which are the casing portion excluding the operation/display panel 8, and are coupled to the main body chassis 1 with cover fixing screws 4. The entire in-vehicle audio equipment set is mounted at an appropriate location inside the vehicle using cent mounting screws 5. The upper and lower covers 3 each have a double structure, and the cover 3 includes an outer plate 6 which is a thin plate that forms the exterior, and a reinforcing frame 7 which is provided inside the plate 6 and has a smaller surface area than the plate 6. are combined.

Next, the effects will be explained.

The parts related to the installation of this set to the car, that is, the parts where the cent mounting screws 5 are connected, must have sufficient strength and are made of iron sheet metal, etc. as in the past, but the parts that are not significantly involved in installation In the case of the main body chassis 1, an opening or notch 1a is provided in the chassis 1 to lower the heat capacity, while in the upper and lower covers 3, an outer plate 6 made of a material with a small heat capacity or a small wall thickness is used to maintain a flat surface and appearance. This forms the outer wall of the cover 3. The minimum strength and flatness of the upper and lower covers 3 are determined by the reinforcing frame 7.
By ensuring this, the outer plate 6 can be made of a thinner material or a material with low strength but low heat capacity.

Further, since the reinforcing frame 7 itself contributes to the heat capacity, it is desired that the reinforcing frame 7 has a volume as small as possible, and is formed to have a much smaller surface area than the outer plate 6. In addition, there may be cases where the cover 3 is required to have even greater strength, but in such cases, the cover h has a double structure as described above, and the inner frame 7 does not affect the appearance. By using a so-called rib structure in the frame 7, the strength can be improved even if the volume is the same, and the strength can also be ensured by providing a support for the main body chassis 1 near the center of the three upper and lower covers. In this case, the heat capacity can be further reduced.

FIG. 2 shows only three parts of the upper and lower covers in FIG. 1 taken out, and in the figure, 9 is the plated part,
This is applied to the outer surface of the outer plate 6. In this case, the plating 9 is a light ray, especially a heat ray (infrared ray).
By selecting a cover with high reflectivity, it is possible to prevent heat from an adjacent heating element from entering the inside of the set.On the other hand, if the main unit itself is a heating element, heat can be prevented from passing through this cover 3. Divergence can be reduced.

The surface treatment of the outer plate 6 may be by plating as in the above embodiment, or by coloring, painting, chemical treatment, etc. In short, the outer surface of the plate 6 may be coated with the above-mentioned material having a high reflectance against light rays, especially heat rays. It is sufficient if surface treatment is applied. Moreover, performing the above-mentioned surface treatment on the inner surface of the outer plate 6 is more effective. It goes without saying that the high reflectance of the casing surface to light rays is also effective in reducing the rise in temperature inside the centrifuge due to irradiation with direct sunlight.

The purpose of the present invention, which is to prevent heat from entering and exiting on the surface of the housing, may raise the question of whether this may have an adverse effect because the heat generated inside the center becomes difficult to escape to the outside, but the set housing has a completely sealed structure. In cases where the set is originally equipped with ventilation holes, most of the heat is dissipated through the vents, and the degree of heat dissipation from the casing surface is small.

〔Effect of the invention〕

As described above, according to the in-vehicle audio equipment according to the present invention, the casing is formed into a double structure consisting of a thin plate forming the outer wall and a frame having a smaller surface area than the outer wall supporting the outer wall. It is possible to obtain a small casing that dissipates heat quickly.Furthermore, by forming a thin film such as plating on the surface of the casing, it is possible to create a casing that is less affected by the heat generated by other sets. There are effects that can be achieved.

[Brief explanation of drawings]

FIG. 1 is a view showing a housing of an in-vehicle audio device according to an embodiment of the present invention, and FIG. 2 is a view showing a cross section of the cover of FIG. 1. In the figure, 3... Upper and lower covers (housing part) 6...
Outer plate (thin plate), 7... Reinforcement frame (frame), 8... Operation/display panel (operation/display section),
9...Plated part. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Masuo Oiwa □ Figure 1 Figure 2

Claims (2)

[Claims] (1) Excluding at least the operation/display part (the housing part is formed in a double structure consisting of a thin plate forming the outer wall and a frame provided inside the thin plate and having a surface area smaller than the thin plate) In-vehicle audio equipment characterized by: (2) The outer surface of the thin plate is coated with a coating that has a higher reflectivity for heat rays or light than the material of the thin plate. The vehicle-mounted audio device according to claim 1, wherein a thin film is formed by plating, coloring, or chemical treatment.